Learn how to send emails with the ESP32 using an SMTP Server. We’ll show you how to send a simple email with HTML or raw text and how to send attachments like images and files (.txt). The ESP32 board will be programmed using Arduino IDE.
In this tutorial, we cover the following topics:
We have a similar tutorial for the ESP8266 board: ESP8266 NodeMCU Send Emails using an SMTP Server: HTML, Text, and Attachments (Arduino)
Introducing SMTP Servers
SMTP means Simple Mail Transfer Protocol and it is an internet standard for email transmission. To send emails using an ESP32, you need to connect it to an SMTP Server.
ESP Mail Client Library
To send emails with the ESP32, we’ll use the ESP-Mail-Client library. This library allows the ESP32 to send and receive emails with or without attachments via SMTP and IMAP servers.
In this tutorial, we’ll use SMTP to send an email with and without attachments. As an example, we’ll send an image (.png) and a text (.txt) file. The files sent via email can be saved in the ESP32 Filesystem (SPIFFS) or a microSD card (not covered in this tutorial).
Installing the ESP-Mail-Client Library
Before proceeding with this tutorial, you need to install the ESP-Mail-Client library. This library is not available to install through the Arduino IDE Library Manager. Follow the next steps to install the library:
- Click here to download ESP-Mail-Client library .zip folder.
- In your Arduino IDE, go to Sketch > Include Library > Add .ZIP Library.
- Select the .zip file you’ve just downloaded.
Then, if you go to File > Examples > ESP-Mail-Client, you’ll find several examples that you can try. You can also access the examples in the library GitHub page—here.
If you’re using the ESP32 with VS Code + PlatformIO, you should copy the following to your platformio.ini file to include the library.
lib_deps = mobizt/ESP Mail Client @ ^1.3.0Sender Email (New Account)
We recommend creating a new email account to send the emails to your main personal email address. Do not use your main personal email to send emails via ESP32. If something goes wrong in your code or if by mistake you make too many requests, you can be banned or have your account temporarily disabled.
We’ll use a newly created Gmail.com account to send the emails, but you can use any other email provider. The receiver email can be your personal email without any problem.
Create a Sender Email Account
Create a new email account for sending emails with the ESP32. If you want to use a Gmail account, go to this link to create a new one.
Create an App Password
You need to create an app password so that the ESP32 is able to send emails using your Gmail account. An App Password is a 16-digit passcode that gives a less secure app or device permission to access your Google Account. Learn more about sign-in with app passwords here.
An app password can only be used with accounts that have 2-step verification turned on.
- Open your Google Account.
- In the navigation panel, select Security.
- Under “Signing in to Google,” select 2-Step Verification > Get started.
- Follow the on-screen steps.
After enabling 2-step verification, you can create an app password.
- Open your Google Account.
- In the navigation panel, select Security.
- Under “Signing in to Google,” select App Passwords.
- In the Select app field, choose mail. For the device, select Other and give it a name, for example ESP32. Then, click on Generate. It will pop-up a window with a password that you’ll use with the ESP32 or ESP8266 to send emails. Save that password (even though it says you won’t need to remember it) because you’ll need it later.
Now, you should have an app password that you’ll use on the ESP32 code to send the emails.
If you’re using another email provider, check how to create an app password. You should be able to find the instructions with a quick google search “your_email_provider + create app password”.
Gmail SMTP Server Settings
If you’re using a Gmail account, these are the SMTP Server details:
- SMTP Server: smtp.gmail.com
- SMTP username: Complete Gmail address
- SMTP password: Your Gmail password
- SMTP port (TLS): 587
- SMTP port (SSL): 465
- SMTP TLS/SSL required: yes
Outlook SMTP Server Settings
For Outlook accounts, these are the SMTP Server settings:
- SMTP Server: smtp.office365.com
- SMTP Username: Complete Outlook email address
- SMTP Password: Your Outlook password
- SMTP Port: 587
- SMTP TLS/SSL Required: Yes
Live or Hotmail SMTP Server Settings
For Live or Hotmail accounts, these are the SMTP Server settings:
- SMTP Server: smtp.live.com
- SMTP Username: Complete Live/Hotmail email address
- SMTP Password: Your Windows Live Hotmail password
- SMTP Port: 587
- SMTP TLS/SSL Required: Yes
If you’re using another email provider, you need to search for its SMTP Server settings. Now, you have everything ready to start sending emails with your ESP32.
Send an Email with HTML or Raw Text with ESP32 (Arduino IDE)
The following code sends an email via SMTP Server with HTML or raw text. For demonstration purposes, the ESP32 sends an email once when it boots. Then, you should be able to modify the code and integrate it into your own projects.
Don’t upload the code yet, you need to make some modifications to make it work for you.
/*
Rui Santos
Complete project details at:
- ESP32: https://RandomNerdTutorials.com/esp32-send-email-smtp-server-arduino-ide/
- ESP8266: https://RandomNerdTutorials.com/esp8266-nodemcu-send-email-smtp-server-arduino/
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files.
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
Example adapted from: https://github.com/mobizt/ESP-Mail-Client
*/
// To send Emails using Gmail on port 465 (SSL), you need to create an app password: https://support.google.com/accounts/answer/185833
#include <Arduino.h>
#if defined(ESP32)
#include <WiFi.h>
#elif defined(ESP8266)
#include <ESP8266WiFi.h>
#endif
#include <ESP_Mail_Client.h>
#define WIFI_SSID "REPLACE_WITH_YOUR_SSID"
#define WIFI_PASSWORD "REPLACE_WITH_YOUR_PASSWORD"
#define SMTP_HOST "smtp.gmail.com"
#define SMTP_PORT 465
/* The sign in credentials */
#define AUTHOR_EMAIL "[email protected]"
#define AUTHOR_PASSWORD "YOUR_EMAIL_PASS"
/* Recipient's email*/
#define RECIPIENT_EMAIL "[email protected]"
/* The SMTP Session object used for Email sending */
SMTPSession smtp;
/* Callback function to get the Email sending status */
void smtpCallback(SMTP_Status status);
void setup(){
Serial.begin(115200);
Serial.println();
Serial.print("Connecting to AP");
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED){
Serial.print(".");
delay(200);
}
Serial.println("");
Serial.println("WiFi connected.");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
Serial.println();
/** Enable the debug via Serial port
* none debug or 0
* basic debug or 1
*/
smtp.debug(1);
/* Set the callback function to get the sending results */
smtp.callback(smtpCallback);
/* Declare the session config data */
ESP_Mail_Session session;
/* Set the session config */
session.server.host_name = SMTP_HOST;
session.server.port = SMTP_PORT;
session.login.email = AUTHOR_EMAIL;
session.login.password = AUTHOR_PASSWORD;
session.login.user_domain = "";
/* Declare the message class */
SMTP_Message message;
/* Set the message headers */
message.sender.name = "ESP";
message.sender.email = AUTHOR_EMAIL;
message.subject = "ESP Test Email";
message.addRecipient("Sara", RECIPIENT_EMAIL);
/*Send HTML message*/
String htmlMsg = "<div style=\"color:#2f4468;\"><h1>Hello World!</h1><p>- Sent from ESP board</p></div>";
message.html.content = htmlMsg.c_str();
message.html.content = htmlMsg.c_str();
message.text.charSet = "us-ascii";
message.html.transfer_encoding = Content_Transfer_Encoding::enc_7bit;
/*
//Send raw text message
String textMsg = "Hello World! - Sent from ESP board";
message.text.content = textMsg.c_str();
message.text.charSet = "us-ascii";
message.text.transfer_encoding = Content_Transfer_Encoding::enc_7bit;
message.priority = esp_mail_smtp_priority::esp_mail_smtp_priority_low;
message.response.notify = esp_mail_smtp_notify_success | esp_mail_smtp_notify_failure | esp_mail_smtp_notify_delay;*/
/* Set the custom message header */
//message.addHeader("Message-ID: <[email protected]>");
/* Connect to server with the session config */
if (!smtp.connect(&session))
return;
/* Start sending Email and close the session */
if (!MailClient.sendMail(&smtp, &message))
Serial.println("Error sending Email, " + smtp.errorReason());
}
void loop(){
}
/* Callback function to get the Email sending status */
void smtpCallback(SMTP_Status status){
/* Print the current status */
Serial.println(status.info());
/* Print the sending result */
if (status.success()){
Serial.println("----------------");
ESP_MAIL_PRINTF("Message sent success: %d\n", status.completedCount());
ESP_MAIL_PRINTF("Message sent failled: %d\n", status.failedCount());
Serial.println("----------------\n");
struct tm dt;
for (size_t i = 0; i < smtp.sendingResult.size(); i++){
/* Get the result item */
SMTP_Result result = smtp.sendingResult.getItem(i);
time_t ts = (time_t)result.timestamp;
localtime_r(&ts, &dt);
ESP_MAIL_PRINTF("Message No: %d\n", i + 1);
ESP_MAIL_PRINTF("Status: %s\n", result.completed ? "success" : "failed");
ESP_MAIL_PRINTF("Date/Time: %d/%d/%d %d:%d:%d\n", dt.tm_year + 1900, dt.tm_mon + 1, dt.tm_mday, dt.tm_hour, dt.tm_min, dt.tm_sec);
ESP_MAIL_PRINTF("Recipient: %s\n", result.recipients.c_str());
ESP_MAIL_PRINTF("Subject: %s\n", result.subject.c_str());
}
Serial.println("----------------\n");
}
}
You need to insert your network credentials as well as set the sender email, SMTP Server details, recipient, and message.
How the Code Works
This code is adapted from an example provided by the library. The example is well commented so that you understand what each line of code does. Let’s just take a look at the relevant parts that you need or may need to change.
First, insert your network credentials in the following lines:
#define WIFI_SSID "REPLACE_WITH_YOUR_SSID"
#define WIFI_PASSWORD "REPLACE_WITH_YOUR_PASSWORD"Insert your SMTP server settings. If you’re using a Gmail account to send the emails, these are the settings:
#define SMTP_HOST "smtp.gmail.com"
#define SMTP_PORT 465Insert the sender email sign in credentials (complete email and app password you created previously).
#define AUTHOR_EMAIL "[email protected]"
#define AUTHOR_PASSWORD "YOUR_EMAIL_PASS"Insert the recipient email:
#define RECIPIENT_EMAIL "[email protected]"Set the message headers in the following lines in the setup()—sender name, sender email, email subject, and the recipient name and email:
/* Set the message headers */
message.sender.name = "ESP";
message.sender.email = AUTHOR_EMAIL;
message.subject = "ESP Test Email";
message.addRecipient("Sara", RECIPIENT_EMAIL);In the following lines, set the content of the message (raw text) in the textMsg variable:
//Send raw text message
String textMsg = "Hello World - Sent from ESP board";
message.text.content = textMsg.c_str();
message.text.charSet = "us-ascii";
message.text.transfer_encoding = Content_Transfer_Encoding::enc_7bit;If you want to send HTML text instead, uncomment the following lines— you should insert your HTML text in the htmlMsg variable.
/*Send HTML message*/
/*String htmlMsg = "<div style=\"color:#2f4468;\"><h1>Hello World!</h1><p>- Sent from ESP board</p></div>";
message.html.content = htmlMsg.c_str();
message.html.content = htmlMsg.c_str();
message.text.charSet = "us-ascii";
message.html.transfer_encoding = Content_Transfer_Encoding::enc_7bit;*/Finally, the following lines send the message:
if (!MailClient.sendMail(&smtp, &message))
Serial.println("Error sending Email, " + smtp.errorReason());Demonstration
Upload the code to your ESP32. After uploading, open the Serial Monitor at a baud rate of 115200. Press the ESP32 Reset button.
If everything went as expected you should get a similar message in the Serial Monitor.
Check your email account. You should have received an email from your ESP32 board.
If you set the option to send a message with HTML text, this is what the message looks like:
If you’ve enable the raw text message, this is the email that you should receive.
Send Attachments via Email with ESP32 (Arduino IDE)
In this section, we’ll show you how to send attachments in your emails sent by the ESP32. We’ll show you how to send .txt files or pictures. This can be useful to send a .txt file with sensor readings from the past few hours or to send a photo captured by an ESP32-CAM.
For this tutorial, the files to be sent should be saved on the ESP32 filesystem (SPIFFS).
Upload files to SPIFFS
To send files via email, these should be saved on the ESP32 filesystem (SPIFFS). We’ll upload a picture and a .txt file to the ESP32 SPIFFS using the ESP32 Filesystem Uploader plugin for Arduino IDE. Follow the next tutorial to install the plugin if you don’t have it installed yet:
Create a new Arduino sketch and save it. Go to Sketch > Show Sketch folder. Inside the Arduino sketch folder, create a folder called data. Move a .jpg file and .txt file to your data folder.
Alternatively, you can click here to download the project folder.
Note: with the default code, your files must be named image.png and text_file.txt. Alternatively, you can modify the code to import files with a different name.
We’ll be sending these files:
Your folder structure should look as follows (download project folder):
After moving the files to the data folder, in your Arduino IDE, go to Tools > ESP32 Sketch Data Upload and wait for the files to be uploaded.
You should get a success message on the debugging window. If the files were successfully uploaded, move on to the next section.
Note: if you start seeing many dots ….____…..____ being printed on the debugging window, you need to hold the ESP32 on-board BOOT button for the files to be uploaded.
Code
The following code sends an email with a .txt file and a picture attached. Before uploading the code, make sure you insert your sender email settings and your recipient email.
/*
Rui Santos
Complete project details at:
- ESP32: https://RandomNerdTutorials.com/esp32-send-email-smtp-server-arduino-ide/
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files.
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
Example adapted K. Suwatchai (Mobizt): https://github.com/mobizt/ESP-Mail-Client Copyright (c) 2021 mobizt
*/
// To send Emails using Gmail on port 465 (SSL), you need to create an app password: https://support.google.com/accounts/answer/185833
// The file systems for flash and sd memory can be changed in ESP_Mail_FS.h.
#include <Arduino.h>
#if defined(ESP32)
#include <WiFi.h>
#elif defined(ESP8266)
#include <ESP8266WiFi.h>
#endif
#include <ESP_Mail_Client.h>
#define WIFI_SSID "REPLACE_WITH_YOUR_SSID"
#define WIFI_PASSWORD "REPLACE_WITH_YOUR_PASSWORD"
#define SMTP_HOST "smtp.gmail.com"
/** The smtp port e.g.
* 25 or esp_mail_smtp_port_25
* 465 or esp_mail_smtp_port_465
* 587 or esp_mail_smtp_port_587
*/
#define SMTP_PORT 465
/* The log in credentials */
#define AUTHOR_EMAIL "[email protected]"
#define AUTHOR_PASSWORD "YOUR_EMAIL_PASS"
/* Recipient's email*/
#define RECIPIENT_EMAIL "[email protected]"
/* The SMTP Session object used for Email sending */
SMTPSession smtp;
/* Callback function to get the Email sending status */
void smtpCallback(SMTP_Status status);
void setup(){
Serial.begin(115200);
Serial.println();
Serial.print("Connecting to AP");
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED){
Serial.print(".");
delay(200);
}
Serial.println("");
Serial.println("WiFi connected.");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
Serial.println();
if (!SPIFFS.begin(true)) {
Serial.println("An error has occurred while mounting SPIFFS");
}
else{
Serial.println("SPIFFS mounted successfully");
}
/** Enable the debug via Serial port
* none debug or 0
* basic debug or 1
*/
smtp.debug(1);
/* Set the callback function to get the sending results */
smtp.callback(smtpCallback);
/* Declare the session config data */
ESP_Mail_Session session;
/* Set the session config */
session.server.host_name = SMTP_HOST;
session.server.port = SMTP_PORT;
session.login.email = AUTHOR_EMAIL;
session.login.password = AUTHOR_PASSWORD;
session.login.user_domain = "mydomain.net";
/* Declare the message class */
SMTP_Message message;
/* Enable the chunked data transfer with pipelining for large message if server supported */
message.enable.chunking = true;
/* Set the message headers */
message.sender.name = "ESP Mail";
message.sender.email = AUTHOR_EMAIL;
message.subject = "Test sending Email with attachments and inline images from SD card and Flash";
message.addRecipient("Sara", RECIPIENT_EMAIL);
/** Two alternative content versions are sending in this example e.g. plain text and html */
String htmlMsg = "This message contains attachments: image and text file.";
message.html.content = htmlMsg.c_str();
message.html.charSet = "utf-8";
message.html.transfer_encoding = Content_Transfer_Encoding::enc_qp;
message.priority = esp_mail_smtp_priority::esp_mail_smtp_priority_normal;
message.response.notify = esp_mail_smtp_notify_success | esp_mail_smtp_notify_failure | esp_mail_smtp_notify_delay;
/* The attachment data item */
SMTP_Attachment att;
/** Set the attachment info e.g.
* file name, MIME type, file path, file storage type,
* transfer encoding and content encoding
*/
att.descr.filename = "image.png";
att.descr.mime = "image/png"; //binary data
att.file.path = "/image.png";
att.file.storage_type = esp_mail_file_storage_type_flash;
att.descr.transfer_encoding = Content_Transfer_Encoding::enc_base64;
/* Add attachment to the message */
message.addAttachment(att);
message.resetAttachItem(att);
att.descr.filename = "text_file.txt";
att.descr.mime = "text/plain";
att.file.path = "/text_file.txt";
att.file.storage_type = esp_mail_file_storage_type_flash;
att.descr.transfer_encoding = Content_Transfer_Encoding::enc_base64;
/* Add attachment to the message */
message.addAttachment(att);
/* Connect to server with the session config */
if (!smtp.connect(&session))
return;
/* Start sending the Email and close the session */
if (!MailClient.sendMail(&smtp, &message, true))
Serial.println("Error sending Email, " + smtp.errorReason());
}
void loop()
{
}
/* Callback function to get the Email sending status */
void smtpCallback(SMTP_Status status){
/* Print the current status */
Serial.println(status.info());
/* Print the sending result */
if (status.success()){
Serial.println("----------------");
ESP_MAIL_PRINTF("Message sent success: %d\n", status.completedCount());
ESP_MAIL_PRINTF("Message sent failled: %d\n", status.failedCount());
Serial.println("----------------\n");
struct tm dt;
for (size_t i = 0; i < smtp.sendingResult.size(); i++){
/* Get the result item */
SMTP_Result result = smtp.sendingResult.getItem(i);
time_t ts = (time_t)result.timestamp;
localtime_r(&ts, &dt);
ESP_MAIL_PRINTF("Message No: %d\n", i + 1);
ESP_MAIL_PRINTF("Status: %s\n", result.completed ? "success" : "failed");
ESP_MAIL_PRINTF("Date/Time: %d/%d/%d %d:%d:%d\n", dt.tm_year + 1900, dt.tm_mon + 1, dt.tm_mday, dt.tm_hour, dt.tm_min, dt.tm_sec);
ESP_MAIL_PRINTF("Recipient: %s\n", result.recipients.c_str());
ESP_MAIL_PRINTF("Subject: %s\n", result.subject.c_str());
}
Serial.println("----------------\n");
}
}
How the code works
This code is very similar to the previous one, so we’ll just take a look at the relevant parts to send attachments.
In the setup(), you need to initialize SPIFFS:
if(!SPIFFS.begin(true)) {
Serial.println("An Error has occurred while mounting SPIFFS");
return;
}You need to create an attachment as follows:
/* The attachment data item */
SMTP_Attachment att;Then, add the attachment details: filename, MIME type, file path, file storage type, and transfer encoding. In the following lines, we’re sending the image file.
att.descr.filename = "image.png";
att.descr.mime = "image/png";
att.file.path = "/image.png";
att.file.storage_type = esp_mail_file_storage_type_flash;
att.descr.transfer_encoding = Content_Transfer_Encoding::enc_base64;Finally, add the attachment to the message:
message.addAttachment(att);If you want to send more attachments, you need to call the following line before adding the next attachment:
message.resetAttachItem(att);Then, enter the details of the other attachment (text file):
att.descr.filename = "text_file.txt";
att.descr.mime = "text/plain";
att.file.path = "/text_file.txt";
att.file.storage_type = esp_mail_file_storage_type_flash;
att.descr.transfer_encoding = Content_Transfer_Encoding::enc_base64;And add this attachment to the message:
message.addAttachment(att);Finally, you just need to send the message as you did with the previous example:
if (!MailClient.sendMail(&smtp, &message, true))
Serial.println("Error sending Email, " + smtp.errorReason());Demonstration
After uploading the code, open the Serial Monitor at a baud rate of 115200 and press the on-board EN/RESET button. If everything goes smoothly, you should get a similar message on the Serial Monitor.
Check the recipient’s email address. You should have a new email with two attachments.
Wrapping Up
In this tutorial you’ve learned how to send emails with the ESP32 using an SMTP Server. For this method to work, the ESP32 should have access to the internet.
If you don’t want to use an SMTP Server, you can also write a PHP script to send email notifications with the ESP32 or ESP8266 board.
You’ve learned how to send a simple email with text and with attachments. When using attachments, these should be save on the ESP32 filesystem (SPIFFS) or on a microSD card (not covered in this tutorial).
The examples presented show how to send a single email when the ESP32 boots. The idea is to modify the code and include it in your own projects. For example, it can be useful to send a .txt file with the sensor readings, send a photo captured with the ESP32-CAM, use deep sleep to wake up your board every hour and send an email with data, etc.
We hope you’ve find this tutorial interesting.
To learn more about the ESP32, take a look at our resources:
- Learn ESP32 with Arduino IDE
- Build Web Servers with ESP32 and ESP8266 eBook
- MicroPython Programming with ESP32 and ESP8266
- More ESP32 resources…
Thanks for reading.
Dear Rui and Sara
Excellent work, this makes me very happy!
Thanks a lot
Best Regards
You’re welcome!
When I run the program, this message appeared
SPIFFS Not Supported on avr
Did you select the ESP32 board? Does your code still compile and upload? Sometimes you’ll see those warning messages and you can ignore them
Hello,
I would like to thank you for your tutorials.
I tried to send email with a wemos D1 mini using the code in this blog and I got the following error:
/home/samorai/Arduino/libraries/ESP32_Mail_Client/src/ssl_client32.h:32:30: fatal error: mbedtls/platform.h: No such file or directory
#include “mbedtls/platform.h”
I am using the latest IDE version.
Any idea how to solve this?
Thanks and regards
Hello,
This issue was solved by downloading https://tls.mbed.org/download/start/mbedtls-2.16.4-apache.tgz and including it in /home/samorai/Arduino/libraries/ESP32_Mail_Client folder.
Regards
Great!
Thanks for sharing that.
Regards,
Sara
Hey whenever I try to upload the code to my ESP32 I keep getting this error and II have no idea what to do. Help!
Arduino: 1.8.17 Hourly Build 2021/09/06 02:33 (Windows 10), Board: “Arduino Uno”
In file included from C:\Users\huntk\Documents\Arduino\libraries\ESP_Mail_Client\src/ESP_Mail_Client.h:112:0,
from C:\Users\huntk\Documents\Arduino\ESP32_Email_Alpha\ESP32_Email_Alpha.ino:20:
C:\Users\huntk\Documents\Arduino\libraries\ESP_Mail_Client\src/extras/ESPTimeHelper/ESPTimeHelper.h:31:10: fatal error: vector: No such file or directory
#include
^~~~~~~~
compilation terminated.
exit status 1
Error compiling for board Arduino Uno.
This report would have more information with
“Show verbose output during compilation”
option enabled in File -> Preferences.
Howdy,
I’ve included this file into my ESP32_Mail_Client folder and still receive the same error when compiling. Does anyone have any solutions?
Thanks
I’ve got the code in my Arduino IDE, but cannot compile. I am seeing the same error.
When I include this folder in src > mbedtls the includes seem to work, but now I have illicited this response from the code. >…/ESP32_Mail_Client/src/ESP32_MailClient.h:37:18: fatal error: ETH.h: No such file or directory
>#include “ETH.h”
I’m going to keep chasing this, but I feel like I have some library mismatch or version wrong. Any insights?
Working with an 8266 – and just realizing as I typed it out that may be the source of my trouble.
Hi Zach.
Unfortunately, this project is not compatible with the ESP8266.
Regards,
Sara
Another top class tutorial from RNT ! Kudos.
I was looking for this exact tutorial for a long time and you guys did it. Worked first shot … both the HTML and Text version mails.
Great. Now I can get a mail when my UPS battery needs charging or when my sump water level drops below the danger mark or …. the list is endless.
That’s great!
I’m glad you found it useful.
Regards,
Sara 😀
Was getting many compilation until I installed version 1.0.4 for ESP32.
Now the first text example works, will try the rest soon,
Thanks!
Compilation errors, I meant.
If you got this obscure error below,
#error: architecture or board not supported
It has to do with the
#include “ESP32_MailClient.h”
is calling an old SD card library,
When I got this error, the compiler is using a very old library that doesn’t recognize ESP32. I removed all the old libraries until the compiler is using the ESP32 SD card library – see below.
Using library SD at version 1.0.5 in folder: C:\Users\one\Documents\Arduino\hardware\esp32\arduino-esp32-master\libraries\SD
Hope this helps!
Hi.
Thanks for sharing that.
I will be helpful for our readers.
Regards,
Sara
I have been looking for exactly this! Just great you posted it.
I have the recommended ESP32 board, but the compiler tells me: “”Error compiling for board DOIT ESP32 DEVKIT V1”. Could you please help me out? Any pointers?
I think A Lee had the same issue, and … the fix. I would like to try it. How do I remove and old library? I know …. rookie question.
When you get the error, what part of the code gets highlighted?
That indicates where the error is.
Regards,
Sara
Thank you for your quick response. In the meantime I have completely removed the entire Arduino installation and its libraries and reinstalled a clean version. It compiles! 🙂
If you go to File Preference and click Show Verbose Output during compilation. Then you will see a lot of messages on the screen. After the compiler stopped, you would see this message on the screen in red.
exit status 1
Error compiling for board ESP32 Dev Module.
Scroll up and see where is error comes from.
C:\Users\One\Documents\Arduino\libraries\SD\src/utility/Sd2PinMap.h:524:2: error: #error Architecture or board not supported.
#error Architecture or board not supported.
^
Sd2PinMap.h is a file under the SD directory. My Google search found not much with this type of error. One poster said the library doesn’t suppose the lastest board. It means sense because the error is Architecture or board not supported.
I figured – the SD library probably is “old”. I started moving it to another drive in my PC and recompile the sketch. Below is the compiler telling which library it was using to compile the sketch.
Multiple libraries were found for “SD.h”
Used: C:\Users\One\Documents\Arduino\libraries\SD
Not used: C:\Users\One\Documents\Arduino\hardware\esp32\arduino-esp32-master\libraries\SD
I moved the SD directory that it was using to another drive.
Then it complied with no error. I scroll up the screen and saw it was using the esp32 library.
Using library SD at version 1.0.5 in folder: C:\Users\One\Documents\Arduino\hardware\esp32\arduino-esp32-master\libraries\SD
It works for me. Good luck!
Thank you A Lee for your extensive response!
Hello, thank you for this tutorial. I am getting the following error message. Your thoughts, please. Thanks, Mac
Connecting to SMTP server…
SMTP server connected, wait for response…
Identification…
Authentication…
Sign in…
Error, login password is not valid
Error sending Email, login password is not valid
Hi.
That means that the password you’ve inserted is not correct for the sender email.
Regards,
Sara
I have the same issue.
I just made the email account, so I know it’s the right PW.
Does it have issue with the ‘#’ symbol?
Andy
Hi Andy.
Double-check that you have access to less secure apps enable.
Sometimes Gmail changes that option without our permission.
Regards,
Sara
Triple checked.
I even set up a new Outlook account to see if it was Gmail.
I get the same error.
Should I try another email?
Andy
Hi Andy.
Honestly, I don’t know.
It worked fine for me using a Gmail account.
If you change to another email provider, check that you have the right smtp settings for that email provier.
Regards,
Sara
Hi,
you should turn on Allow less secure apps on Gmail. This will solve your problem.
Hello Macin,
I get the same issue but not always. Issue does not come from my password or Id because sometimes it works ! did you find a solution to your issue ?
I’ve had the same issue, though the password was correct. I’ve done the following and it now works well:
– Enable less secure apps
– Enable 2-Step verification
– Then Manage your google account>Security>Sign in to Google>App password>create a new app password which can only be used in the device you choose.
The generated password should be placed on the arduino sketch replacing your main accounts password.
If you have several ESP32 (or other devices) you should generate an app password per device.
Hope this helps.
would you share the place where i should place the app password in the Arduino ide code?
Hi.
Insert it on the following line:
#define AUTHOR_PASSWORD “YOUR_EMAIL_PASS”
Regards,
Sara
Hello, First of all, thanks for this post.
I want to send an email when my Magnetic switch is HIGH. Magnetic Switch is connected to ESP32. So in which part of the code I should add this?
It might be a simple question but I am new in Arduino, and ESP32, so please help me.
Hello and well done for your work.
I am new to the subject and I don’t know what “SSID” is or where to find it.
Thank you for informing me.
Regards
Hi Jean.
SSID is the name of your internet network (Wi-Fi).
Usually, there’s a sticker below the router with the wi-fi name.
Also, if you search for Wi-Fi networks with your smartphone, you’ll find its name.
Regards,
Sara
Thank you for your reply Sara.
Regards.
Hi all, is there a library like “ESP32_MailClient.h” for ESP8266?
Or how can I use this code for ESP8…
Hi Tom.
This code is not compatible with ESP8266.
You can use this library to send emails with ESP8266: https://github.com/xreef/EMailSender
Regards,
Sara
dear if I want to send voltage value , what I should do since smtpData.setMessage(“ALI SHAMI testing “, false); support only char . thxx in advance
Hi.
You can take a look at this project that sends temperature values via email. Instead of temperature values, you can send voltage.
https://randomnerdtutorials.com/esp32-email-alert-temperature-threshold/
You need something as follows, for example:
String emailMessage = String(“Testing: “) + String(voltage)
Then, use:
smtpData.setMessage(emailMessage, true);
I hope this helps.
Regards,
Sara
Hello, thank you very much for the publications, you are great.
I have finished your project and I receive the email without the files, this is what I see on the serial monitor:
Connecting
WiFi connected.
Preparing to send email
Connecting to SMTP server …
SMTP server connected, wait for response …
Identification …
Authentication …
Sign in …
Sending Email header …
Sending Email body …
Sending attachments …
Finish …
Finished
Email sent successfully
—————-
however in the “data” folder are your files. Sorry if it’s a silly question but I’m a newbie.😊
Hi Rafa.
Thanks for your question. Did you upload the files to the ESP32 SPIFFS?
After moving the files to the data folder, you need to go to Tools > ESP32 Data Sketch Upload
Regards,
Sara
Thanks for your response and sorry for the delay. It is possible that this is the problem, I have several Arduino installations and maybe it confused me. Thank you
Hi Rafa.
Use only one Arduino installation to avoid problems and conflicts with libraries.
Regards,
Sara
Dear Rui and Sara
I thank U for your Excellent work,
I have a liiiitle problem with the attached file: it is on the SD card and I the error is in this lines :
MailClient.sdBegin(18, 19, 23, 5); // (SCK, MISO, MOSI, CS)
if(!SD.begin()){
Serial.println(“Card Mount Failed”);
return “”;
}
the error is : exit status 1
return-statement with a value, in function returning ‘void’ [-fpermissive]
I beg your help, superplease!
Simplemente borra las comillas es un error de tecleado.
Hi Rui and Sara,
It is awesome…thank you so much. Works as expected at first try with Gmail account.
Best regards,
Tondium
Great! 🙂
Hi,
when I compile the sketch send email on a ESP32 dev board, I get several compiler errors. Which library is missing?
Here the errors:
/Users/myName/Documents/Arduino/hardware/espressif/esp32/libraries/ESP32-Mail-Client/src/ssl_client32.cpp: In function ‘int start_ssl_client(sslclient_context32*, const char*, uint32_t, int, const char*, const char*, const char*, const char*, const char)’:
/Users/myName/Documents/Arduino/hardware/espressif/esp32/libraries/ESP32-Mail-Client/src/ssl_client32.cpp:101:48: error: cannot call member function ‘int WiFiGenericClass::hostByName(const char, IPAddress&)’ without object
if (!WiFiGenericClass::hostByName(host, srv))
^
/Users/myName/Documents/Arduino/hardware/espressif/esp32/libraries/ESP32-Mail-Client/src/ssl_client32.cpp:271:85: error: ‘mbedtls_ssl_conf_psk’ was not declared in this scope
(const unsigned char *)pskIdent, strlen(pskIdent));
^
/Users/myName/Documents/Arduino/hardware/espressif/esp32/libraries/ESP32-Mail-Client/src/ESP32_MailClient.cpp: In member function ‘bool ESP32_MailClient::waitIMAPResponse(IMAPData&, uint8_t, int, int, int, std::__cxx11::string)’:
/Users/myName/Documents/Arduino/hardware/espressif/esp32/libraries/ESP32-Mail-Client/src/ESP32_MailClient.cpp:2460:9: error: ‘transform’ is not a member of ‘std’
std::transform(tmp.begin(), tmp.end(), tmp.begin(), ::tolower);
^
/Users/myName/Documents/Arduino/hardware/espressif/esp32/libraries/ESP32-Mail-Client/src/ESP32_MailClient.cpp:2629:13: error: ‘sort’ is not a member of ‘std’
std::sort(imapData._msgNum.begin(), imapData._msgNum.end(), compFunc);
^
/Users/myName/Documents/Arduino/hardware/espressif/esp32/libraries/ESP32-Mail-Client/src/ESP32_MailClient.cpp: In member function ‘void IMAPData::setFetchUID(const String&)’:
/Users/myName/Documents/Arduino/hardware/espressif/esp32/libraries/ESP32-Mail-Client/src/ESP32_MailClient.cpp:3702:3: error: ‘transform’ is not a member of ‘std’
std::transform(tmp.begin(), tmp.end(), tmp.begin(), ::toupper);
^
Is there still a chance that I get an answer to my question? Thanks!
Hi Kurt.
I’m sorry for taking so long to see your comment.
I think you have some problem with the library.
I suggest that you delete the library from the libraries folder and try to install it again.
Regards,
Sara
Love this project, easy to follow and understand. Works great until I use a battery to power the ESP32. I tried different cables,batteries, power supply with no success in sending. Nothing happens. Plugged it into a wall jack with the 5v adapter and it works fine.
What am I missing.
Hi Karel.
What battery are you using to power the ESP32?
You can take a look at this project (ignore the solar panels, just take a look at the battery side): https://randomnerdtutorials.com/power-esp32-esp8266-solar-panels-battery-level-monitoring/
Regards,
Sara
Hi Sara
I’m using a 9V with the ardunio power board and have also tried the LM317 regulator set to 5v. No go. As soon as I switch to the micro usb email arrives no problem.???
I’m at a loss?
hello,
can you set this project to work that
door status monitormade by you? because that project doesnt work anymore because of IFTTT upgrade….thanks
The code works great, my question is how to add multiple recipients for a message.
Once again – brilliant tutorial – many thanks
I appreciate this is old but may help others.
Define the other recipient email addresses as Carbon Copies
eg:
message.addCc(RECIPIENT_CC1);
message.addCc(RECIPIENT_CC2);
you can also send Blind Carbon Copies
message.addBcc(RECIPIENT_BC);
Hi Guys!
I was trying to send a sensor value (MQ-2) by e-mail, using the Wemos Lolin Oled and your code. But all the analog input PINs go to 100%… And I don’t know why!
Do you have some idea that is happening?
Best,
Ricardo
Sorry! Without the email code, I can see the sensor value on Oled display. But when the email code is added, the sensor value goes to 4095…
Hi Ricardo.
You’re probably using an ADC2 analog pin.
ADC2 doesn’t work well with Wi-Fi.
You must choose an ADC1 pin. See the ESP32 pinout guide here: https://randomnerdtutorials.com/esp32-pinout-reference-gpios/
Regards,
Sara
Thank you!
In fact, I’m using the Esp32 Oled board. But I connected the sensor to GPIO 36 (that’s an ADC1) and now the analogRead () is working.
Thanks again!
Ricardo
Is there any requirement of doing some connections with esp32.
Hi.
What do you mean?
Connections with sensors and outputs?
Take a look at this guide: https://randomnerdtutorials.com/esp32-pinout-reference-gpios/
Regards,
Sara
Thanks the Santos to provide a lot of good projects on this site. One of my struggles is to know what IP is assigned to a “webserver” by the wireless router if there is no “display” available to show the IP address. Below are the changes that I made to the test email sketch to make it possible.
Modify the emailSubject as a String; add localIP as a variable
String emailSubject;
IPAddress localIP;
Add the following at the end of the Setup
Serial.print(“IP: “);Serial.println(WiFi.localIP());
localIP = WiFi.localIP();
emailSubject =String( localIP[0]) + “.” + String( localIP[1])+ “.” + String( localIP[2]) + “.” + String( localIP[3]);
SMTPsendmail();
When you receive the email from your project, the IP address is on the Subject.
Have fun!
Hello! Thanks for your input Santos and Lee, I really needed this. But I have a problem when you declare SMTPsendmail();. Does this function belong to the library? Why am I getting the error: ‘SMTPsendmail’ was not declared in this scope?
Are you using the latest version of the ESP32 boards installation (Tools > Boards > Boards Manager, search for ESP32 and update to the latest version)?
Are you using the latest version of the library?
Are you using this code on an ESP32?
Regards,
Sara
Rui and Sara, I’m here from BRasil to accompany you. Congratulations!
Which command do I use to delete the SPIFFS file after it is sent?
Hi.
You can use the following command:
SPIFFS.remove(“/filename”);
Replace filename with the name of the file you want to remove. You also need to include the file extension.
Regards,
Sara
What about new version ESP32_Mail_Client.h?
Is it necesary to change?
Thanks a lot
Hello, great article and this library is working very well ! Thanks.
Thanks for this awesome tutorial.
I can generate an email when the code is placed in setup(), but if I place it anywhere else I get
[E][ssl_client32.cpp:63] handle_error(): SSL – Memory allocation failed
[E][ssl_client32.cpp:65] handle_error(): MbedTLS message code: -32512
[E][WiFiClientSecureESP32.cpp:179] connect(): start_ssl_client: -32512
Any idea why this might be happening?
Thanks for any clues!
Further info: when placed before (blocking) BLE scan function, no problem, when placed after, fails. So some resource used by BLE scan is preventing email?
Hey Nancy,
Did you ever get a resolution to this problem? I see the same issue, can’t successfully place the email sending code in “loop”. (ESP32)
Thanks, Jim
When using with Gmail, as we know we have to enable the low security mode on the Gmail account in question.
But there is a problem in that if you don’t often send an email using this account Google will automatically turn that function back off again after a certain period of time ( how long ? – I don’t know)
and your account will now
I have that working fine, but in my case I only want to send a notification email as a very sporadic event
This means there is a good chance that Google have disabled the low security mode again and my notification email will fail to get thru
Is there some function/command ( other than an sending a spurious email) I can send to the gmail account (say once a day/week) to keep the account awake and ensure that Google don’t change the low security mode against my wishes
Hi, I suggest to send an “I’m alive” email once a week, or so.
Yes – thats what I decided to do in the end
That email acts as the confirmation to me that Gmail is still working
(currently it gets sent every night @ 00:00 – possibly overkill)
Hi,
i am trying and following al of the sketches ,
but i keep getting :
‘SMTPData’ does not name a type.(just copied the code)
can you tell me how to fix this? and why this happens
i used the latest esp32 mail client
thanks
I had the same error, but it was because I had a brain fart. Be sure the correct board type is selected in your Arduino IDE.. In my case I had a non ESP32 Board selected in error.
Hi, did you find the solution? I’m having the same problem – the correct board is selected and all the libraries should be up to date.
thanks!
Not sure if this has been already mentioned, but it’s not a good idea to make the gmail account “less secure”. Instead, create a pecial password at “Sign in with App Passwords”.
Best regards.
i would love to interface a gps sensor with esp32 and send a panic email and text message with the gps location everytime danger is sensed by a person holding the device. the device could be a bag with a push button
Very well-written tutorial. Great work. Thank you.
Thanks 🙂
why dont we use LittleFS in esp32?
I am getting an error report: ‘ESP_MAIL_PRINTF’ was not declared in this scope
What could be the reason for this error report?
Hi.
What’s the board that you’re using?
MAke sure you are using the latest version of the library.
Regards,
Sara
I found the answer to my question: there was an old version of the ESP_Mail_Client.h in my libraries folder, which was used during compialtion. Deleting that old version solved the problem.
Yes. That was what I thought.
Regards,
Sara
Yes indeed, good thinking. Thank you very much
Thanks Sara and Rui for such a complete, clear and educational tutorial! It was just what I needed. I will definitely be checking out your other tutorials. The demo code works great on my Adafruit Feather Huzzah32 board, with Yahoo email.
A tip for Yahoo email users: I used “smtp.mail.yahoo.com” and port 465. I received “authentication failure” messages using my normal login and password. The only solution I found was to create an “App Password” on your Yahoo account web page (Account Info -> Account Security -> look for App Password section). Use the App Password in place of your normal password, and it works great!
Thanks for sharing that tip.
Regards,
Sara
Hi Rui and Sara,
Thank you for all the good and well structered information in all your tutorials. You’re the best!
In this one, I have a particular doubt.
I implemented this on my ESP32 and have sended emails with HTML (no attachements). Worked perfectly.
Is it possible to insert in the “String htmlMsg” arduino variables? How should I do that?
For example:
String htmlMsg = ”
Hello World!Energy consumed: INSERT HERE ARDUINO VARIABLE
“;
Thank you in advance!
Hi.
Yes, you can concatenate the htmlMsg String with arduino variables.
Regards,
Sara
Hey, I love your tutorials.
I tried your code month ago and it went great.
But now I got back to different project and it doesn’t work.
After the message “starting socket” I always get an error message “could not get ip from host”.
Can you please help me?
Having an ESP send an email is a feature I took one step further, most cellular phone providers allow a feature they don’t tell many people about. In most cases you will need to contact the tech support to activate it.
It can take several minutes to receive an email, depending on the frequency your device checks for new email. Receiving a text message is usually much quicker. Did you know you can send a plain text email message to your cellular phone number and receive it as a text message?
For an example, I have a google mail account. I have also rigged up a 433 RF receiver to an ESP32. When an RF transmitter button is pressed and identified by the ESP, it sends an email to [email protected] and within a few seconds I receive a text message on my cellular phone.
That’s a great tip!
Thanks for sharing.
Regards,
Sara
Excellent!!!
I learn so much from your examples. Thank you!
Once again – great tutorial – many thanks.
Will you be doing another one for receiving emails?
I want to email configuration details to my ESP32 either within the message contents or as an attached text file which I can then write to flash memory. This will be much better and easier than having to use the arduino ‘upload’ and can be done without having to use the Arduino IDE.
Hi.
At the moment, we don’t have any tutorials about readings emails.
But take a look at the following examples that might help:
https://github.com/mobizt/ESP-Mail-Client/tree/master/examples/IMAP
Regards,
Sara
Dear Rui and Sara,
Thanks very much for this tutorial. The first part, sending STMP e-mail message with my ESP32 worked perfectly which is why I was surprised at receiving the following error when trying to compile the Send Attachments tutorial. I was particularly surprised since the sketches are very similar. I performed the SPIFFS plug-in and attachment upload OK and copied over your exact code without changing any of the WiFi, or e-mail parameters as a double check and still received the errors. Error message text follows bellow:
ESP_Email_Attachments:43: error: redefinition of ‘SMTPSession smtp’
SMTPSession smtp;
^
C:\Users____\Documents\Arduino\sketch_nov18a\sketch_nov18a.ino:42:13: note: ‘SMTPSession smtp’ previously declared here
SMTPSession smtp;
^
C:\Users____\Documents\Arduino\sketch_nov18a\ESP_Email_Attachments.ino: In function ‘void setup()’:
ESP_Email_Attachments:48: error: redefinition of ‘void setup()’
void setup(){
^
C:\Users____\Documents\Arduino\sketch_nov18a\sketch_nov18a.ino:47:6: note: ‘void setup()’ previously defined here
void setup(){
^
C:\Users____\Documents\Arduino\sketch_nov18a\ESP_Email_Attachments.ino: In function ‘void loop()’:
ESP_Email_Attachments:146: error: redefinition of ‘void loop()’
void loop()
^
C:\Users____\Documents\Arduino\sketch_nov18a\sketch_nov18a.ino:145:6: note: ‘void loop()’ previously defined here
void loop() { }
^
C:\Users___\Documents\Arduino\sketch_nov18a\ESP_Email_Attachments.ino: In function ‘void smtpCallback(SMTP_Status)’:
ESP_Email_Attachments:151: error: redefinition of ‘void smtpCallback(SMTP_Status)’
void smtpCallback(SMTP_Status status){
^
C:\Users____\Documents\Arduino\sketch_nov18a\sketch_nov18a.ino:148:6: note: ‘void smtpCallback(SMTP_Status)’ previously defined here
void smtpCallback(SMTP_Status status){
^
Multiple libraries were found for “WiFi.h”
Used: C:\Users___\AppData\Local\Arduino15\packages\esp32\hardware\esp32\1.0.1\libraries\WiFi
Not used: C:\Program Files (x86)\Arduino\libraries\WiFi
Multiple libraries were found for “SD.h”
Used: C:\Users\loren\AppData\Local\Arduino15\packages\esp32\hardware\esp32\1.0.1\libraries\SD
Not used: C:\Program Files (x86)\Arduino\libraries\SD
exit status 1
redefinition of ‘SMTPSession smtp’
Hi.
It seems you didn’t copy the code correctly. Can you check it again?
I just tested that code and it is compiling just fine.
Regards,
Sara
Sara,
Thank you so much for your response. Yes, it works fine. Initially, I had been copying the code from the window within the tutorial. This time I copied from the “VIEW RAW CODE” option and it compiled OK. Could there be a slight difference between the two?
Hi.
No, the codes are the same.
You must have copied something twice. I recommend always copying the code from the VIEW RAW CODE option.
Regards,
Sara
Hi,
I just tried this code, which is working fine (ESP32).
A little note : Google mail does not provide the “Less Secure App” option anymore. Instead, you must create an App password. Same for Yahoo.
Just one question: I noticed the constant decrease of the Heap value.
Is there a way to prevent this to happen? If you leave the system unattended for a while, one could run out of memory.
I checked the library source code, but could not find anything related to this point.
Thanks,
Thierry
Thanks for sharing that.
I updated the tutorial to login with an app password.
I’m not sure what’s the answer to your question. Maybe it is better to ask the library’s developer?
Regards,
Sara
Sara & Rui,
This worked fine on a m5stamp-c3 (esp32).
Very good work.
Small is beautiful !!
Best regards
Cemal
Hello,
I am French man, be indulgent with my English!
I try to use your example with a SD card File (it run well with SPIFFS), where I logged data every minutes.
First I initialize a SD card:
if (!SD.begin(4))
{
cardOK_g= 0;
Serial.println(“Card failed, or not present je mets cardOK à 0”);
}
….
Then I just modify the line
att.file.storage_type = esp_mail_file_storage_type_flash;
By
att.file.storage_type = esp_mail_file_storage_type_sd;
I got the message :Sending attachments…
Peisey1.txt
did I forgot something?
Thank a lot
Gilles from Paris
Hi.
I’m not sure.
I also tried it with an SD card some time ago and wasn’t able to make it work. However, I don’t remember what was exactly my problem.
Regards,
Sara
Olá!
O código funciona perfeitamente, porem tem alguma forma para que a notificação de alerta seja envia para três e-mails diferentes?
Olá!
É possível enviar para mais deu um e-mail a notificação de alerta?
Hi, congratulations for your code…but i wanted know if is possible a sucess in ESP01 (8266)..
Hi.
Yes. It should work on an ESP-01. But, you’ll need to follow the next tutorial instead: https://randomnerdtutorials.com/esp8266-nodemcu-send-email-smtp-server-arduino/
Regards.
Sara
Thank you so much for updating this code to add 2-step-verification. My outdoor mailbox was very quiet lately and then I found out GMAIL didn’t support unsafe devices anymore since 30 May. You guys saved me from a lot of work. Thanks again!!
Very cool project you shared on that youtube link!
That looks great!
Thanks for great tutorial – it works perfectly but how to use it in a real-world sense? Sorry if this is dumb question but it would be more useful to me if the recipient email address was not hard coded. I pull the recipient address out of a cloud data store for my application. Is there a way to not hard code the to_address at compile time and send to the address my app has stored in a String or Char array?
Nevermind – String recipient_address “[email protected]” at runtime works great!
Good afternoon,
Is this being updated for the new google security requriements. I am getting an error:
< S: 534-5.7.9 Application-specific password required. Learn more at
< S: 534 5.7.9 https://support.google.com/mail/?p=InvalidSecondFactor n20-20020a05620a223400b006a6b564e9b8sm6067424qkh.4 – gsmtp
Error, authentication failed
Never mind figured it out. I would paste above the following section:
#define AUTHOR_PASSWORD “YOUR_EMAIL_PASS”
That’s where you put the app password you generated for overlogged newbs like me.
I got the error:
undefined reference to `smtpCallback(SMTP_Status)’
collect2: error: ld returned 1 exit status
How to fix this ?
Thx
You need to copy the callback at the bottom too.
Thanks for updating this to accommodate Google’s elimination of “less secure devices”. Great tutorial. My only problem was that after creating the app password, I was getting an error due to authentication failed. I finally realized that I had to open my Google email and acknowledge that I had set up the app password. After that, it worked! You may want to add this to your instructions. Thanks again. -Tom
Hi.
Great!
Thanks for letting us know.
Regards,
Sara
Hi,
Perhaps this was already commented, but because it’s not reflected in the code, I’m mentioning it here.
There’re typos on two lines towards the end. These are the corrections:
// ESP_MAIL_PRINTF(“Recipient: %s\n”, result.recipients);
// ESP_MAIL_PRINTF(“Subject: %s\n”, result.subject);
ESP_MAIL_PRINTF(“Recipient: %s\n”, result.recipients.c_str());
ESP_MAIL_PRINTF(“Subject: %s\n”, result.subject.c_str());
Trying this and keep getting errors.
Connecting to SMTP server…
Hi.
What’s your ESP32 boards version? Tools > Board > Boards Manager > Search for ESP32 and check the version.
Regards,
Sara
Platform firebeetle32:[email protected] already installed
I suggest checking if there are any board updates and try to compile and run the code again.
I had the same issue with my DOIT ESP32 DEVKIT.
I was sceptical about the proposed solution, but I tried anyway.
So I ran an update for the board from 1.0.2 to 1.0.6 in the boardmanager.
AND IT WORKED!!!!!!
So thank you very much Sara for this solution.
That’s great!
I’m glad it worked!
REgards,
Sara
Hello,
My ESP32 Devkit 1 (wrover module) sketch is successfully sending email using my ISP’s SMTP connection (not gmail), but it fails after two sent emails. Any further emails generate error:
Connecting to SMTP server…
I can immediately restart my ESP32 and it can then send emails, but no more than two. That indicates that my ISP isn’t rejecting the connection due to spamming or flooding.
I am waiting between email attempts to prevent my ESP from locking me out due to flooding or spamming protection.
In the exact example sketch above (“CODE”) I added to send more than one email:
delay(60000);
Serial.println(“\nSending an email 2”); // Start sending Email and close the session
if (!MailClient.sendMail(&smtp, &message))
Serial.println(“Error sending Email, ” + smtp.errorReason());
delay(60000);
Serial.println(“\nSending an email 3”); // Start sending Email and close the session
if (!MailClient.sendMail(&smtp, &message))
Serial.println(“Error sending Email, ” + smtp.errorReason());
Any ideas?
Thanks, Jim
Hi Jim.
What happens when it fails?
Do you get any errors in the Serial Monitor?
Regards,
Sara
Also…
I added at the end of the exact example sketch above a delay and ESP restart:
if (!MailClient.sendMail(&smtp, &message))
Serial.println(“Error sending Email, ” + smtp.errorReason());
Serial.println(“One minute delay before ESP restart”);
delay(60000);
Serial.println(“\nRestarting to send another email”);
ESP.restart();
So it sends an email, delays and restarts the ESP, which sends an email, delays, restarts…..
This version reliably sends an email every minute or so, which is successfully received. This demonstrates that my ESP’s SMTP session isn’t blocking my test emails as an anti spam or anti flooding measure.
If I send multiple emails in the sketch, one per minute, only the first two are successful, with the rest resulting in:
C: Wait for NTP server time synching
Error, unable to connect to server
Is there a way to terminate the SMTP session and restart it before every sending emails?
Thanks for any recommendations.
Hi.
Supposedly the email session is closed automatically right after sending the email…
Try to add the following line after sending the email:
smtp.sendingResult.clear();Let me know if that solves the issue.
Regards,
Sara
Hello, Thank you for this tutorial.I was able to send the email successfully but the image and the text files are not showing in the mail,how can I fix this please?
The following error occurs when compiling Send_Photos_Email.ino.
‘SMTPData’ does not name a type
Hi.
did you install the required library?
What’s the version of the library you’re using?
Regards,
Sara
thanks for the wonderful example, I want to expand it to send email attachment from SD Card , can you please tell me how I can attach file from SD card?
hi Sara
is my post deleted ? I had posted a question today on how to use this example to send attachment from SD card but I dont see it here.
please advise
Hi.
Most comments need to be approved before they are published.
There’s an example in the library examples folder that shows how to do that: https://github.com/mobizt/ESP-Mail-Client/blob/master/examples/SMTP/Send_Attachment_Flash/Send_Attachment_Flash.ino
I hope this helps.
Regards,
Sara
Hello Sara,
thank you for the scripts, they are great and easy to use.
But please fix the code like Emilio wrote on July 6, 2022.
Regards
Nils
Thanks.
Done.
Maybe you should als include emilio’s idear not to make the google account insecure as this is exposed to the internet?
Not sure if this has been already mentioned, but it’s not a good idea to make the gmail account “less secure”. Instead, create a pecial password at “Sign in with App Passwords”.
Best regards.
We recommend using an App password.
We have a section explaining how to use an APP password: see the section “Create an App Password” in the current post.
Regards,~
Sara
Good evening, I have successfully loaded this project, ESP32 card but I can’t compile it I get this error, if anyone can help me. thank you
— ecco errore compilatore —
In file included from F:\ESP32_ESP8266_RANDOM_NERD_TUTORIALS\RuiSantos_invia_mail\RuiSantos_invia_mail.ino:20:0:
c:\Users\paolo\Documents\Arduino\libraries\ESP-Mail-Client-master\src/ESP_Mail_Client.h:55:17: fatal error: ETH.h: No such file or directory
compilation terminated.
exit status 1
Compilation error: exit status 1
Hi Sara,
email received with no attachment .
I uploaded the 2 files using esp32 sketch data upload and said file uploaded.
then I uploaded the email code with no error.
Sending attachments…
image.png
text_file.txt
Here is the error from the serial : but email received with no attachment .
E (4016) SPIFFS: mount failed, -10025
SPIFFS mounted successfully
Connecting to SMTP server…
Hi.
Are you using LittleFS for ESP32?
I am using #include <SPIFFS.h>
do I have to upload the library for LittleFS for ESP32 and define it ?
Thanks
No.
But I don’t understand why you’re getting an issue related to littlefs :/
Regards,
Sara
email received with no attachment.
am getting these error.
SPIFFS mounted successfully
./components/esp_littlefs/src/littlefs/lfs.c:1229:error: Corrupted dir pair at {0x0, 0x1}
E (28343) esp_littlefs: mount failed, (-84)
E (28344) esp_littlefs: Failed to initialize LittleFS
My Code :;;;;;;;;;;;;;;;;;;
#include <Arduino.h>
#if defined(ESP32)
#include <esp_littlefs.h>
#include <SPIFFS.h>
#include <WiFi.h>
#include <ESP_Mail_Client.h>
#define WIFI_SSID “…..”
#define WIFI_PASSWORD “……..”
my question is why I am geeting esp_littlefs: mount failed ?
do I need SD card connected to my esp32 ?
Thanks
Hello; Was great, but it’s no more possible to using gmail stmp by now, new security conditions 🙁 regards. hervema
Yes it’s possible! Read all the comments here or https://support.google.com/accounts/answer/185833?hl=en
You CAN send emails from gmail (i’m doing it) but have to turn on ‘2-Step Verification’
1 Open your Google Account.
2 In the navigation panel, select Security.
3 Under “Signing in to Google,” select 2-Step Verification. Get started.
4 Follow the on-screen steps.
Hi,
First of all, thanks for the tutorial.
I tried to combine smtp and firebase real time database in the same board, and the code is not working (used the ones that are provided in this website). Does the board have any constrains or can smtp and sending data to firebase realtime database work together?
Thanks in advance
Hi, Excellent and practical application as usual.
Not sure if this is libray or coding issue or a (more recent) gmail issue.
The emails send according to the serial monitor and can be seen on the gmail account sent list. – however they never arrive (or perhaps were never actually sent). I tried several recipient addresses.
If subsequently manually forwarding them from gmail sent list they go thru.
Any ideas???
Thanks
Hello,
thank you for a great tutorial, I learned a lot from it (and other tutorials on your site)! I am trying to combine this project with WifiManager and the deep sleep function with the idea to set up the wifi credentials, collect additional variables (using spiffs) via phone and then run the code and send periodic email notifications. The three projects run well in isolation and the code compiles and runs. After executing the mail sending function though, I get following error message:
Corrupted dir pair at {0x0, 0x1}
E (28343) esp_littlefs: mount failed, (-84)
E (28344) esp_littlefs: Failed to initialize LittleFS
After that, the ESP32 reboots and loses the previously stored data.
Do you happen to have any idea what would cause that? Would you have an example of combining the WifiManager and email sending capability?
Appreciate your help!
Hi.
Try to use SPIFFS instead of littleFS.
Regards,
Sara
Thank you Sara for your reply!
I have tried that, but it does not seem to work either. There seems to be a memory conflict between WiFiManager, the Sendmail function and/or deep sleep. The code is too long to post in full here, but perhaps the below extract of the error messages in sequence can give a clue?
Thank you.
//Declarations used:
#define ESP_DRD_USE_SPIFFS true
#include
#include <Arduino.h>
#include <WiFi.h> // WiFi Library
//#include <FS.h> // File System Library
#include <SPIFFS.h> // SPI Flash System Library
#include <WiFiManager.h> // WiFiManager Library
#include <ArduinoJson.h> // Arduino JSON library
#include <ESP_Mail_Client.h>
#include “DHT.h” //library for humidity and temperature sensor
#define JSON_CONFIG_FILE “/test_config.json” // JSON configuration file
//The function to save data in memory==>:
bool loadConfigFile()
// Load existing configuration file
{
// Uncomment if we need to format filesystem
//SPIFFS.format();
// Read configuration from FS json
Serial.println(“Mounting File System…”);
// May need to make it begin(true) first time you are using SPIFFS
if (SPIFFS.begin(false) || SPIFFS.begin(true))
{
Serial.println(“mounted file system”);
if (SPIFFS.exists(JSON_CONFIG_FILE))
{
// The file exists, reading and loading
Serial.println(“reading config file”);
File configFile = SPIFFS.open(JSON_CONFIG_FILE, “r”);
if (configFile)
{
Serial.println(“Opened configuration file”);
StaticJsonDocument json;
DeserializationError error = deserializeJson(json, configFile);
serializeJsonPretty(json, Serial);
if (!error)
{
Serial.println(“Parsing JSON”);
strcpy(testString1, json["testString1"]);testNumber1 = json["testNumber1"].as<int>();
testNumber2 = json["testNumber2"].as<int>();
strcpy(testString2, json["testString2"]);
strcpy(testString3, json["testString3"]);
strcpy(testString4, json["testString4"]);
testNumber3 = json["testNumber3"].as<int>();
testNumber4 = json["testNumber4"].as<int>();
testNumber5 = json["testNumber5"].as<int>();
testNumber6 = json["testNumber6"].as<int>();
strcpy(testString5, json["testString5"]);
strcpy(testString6, json["testString6"]);
return true;
}
else
{
// Error loading JSON data
Serial.println("Failed to load json config");
}
}
}
}
else
{
// Error mounting file system
Serial.println(“Failed to mount FS”);
}
return false;
}
void saveConfigCallback()
// Callback notifying us of the need to save configuration
{
Serial.println(“Should save config”);
shouldSaveConfig = true;
}
//I get following results and errors::
//1st iteration of the program. The send mail function works properly and uses stored data to send email, however it returns following error message
//Error message after send mail activation (stored data are lost and reversed to original settings):
same for me, after a lot of bloody head scratching i’ve found that a roll-back to v1.0.6 esp 32 board definition (from https://dl.espressif.com/dl/package_esp32_index.json) and the use of lorol LittleFS_esp32 library
the issue is probably in partitions.csv
cheers 🙂
The library now uses LittleFS by default instead of SPIFFS.
You just need to replace all the “SPIFFS” in your sketch with “LittleFS”.
We’ll update the code soon.
Regards,.
Sara
Hello Sara
your “ESP32-CAM: Take and Send Photos via Email using an SMTP Server” example uses SPIFFS. I noticed that picture storage can fail repeatedly (0 bytes saved) before an image is stored. I then read SPIFFS is deprecated and we’d better use LittleFS. However, by replacing SPIFFS with LittleFS (or LITTLEFS? confusione about that – multiple libraries found) I get an error on smtpData.setFileStorageType(…) which doesn’t seem to accept LittleFS.
Now I see you saying that the library (which one?) uses LittleFS by default, not SPIFFS – and you plan to update your code.
Can you shed some light please?
Regards,
Michele
Hi.
The library we use to send the emails now uses LittleFS by default.
I’m currently out of the offie now, so I can’t update the code.
Basically, you just need to replace all words “SPIFFS” with “LittleFS” in your code.
Let me know if that solves the problem.
Regards,
Sara
Hello Sara,
thank you for your quick reply.
I had tried already to replace the word “SPIFFS” by “LittleFS”, but the expression “smtpData.setFileStorageType(MailClientStorageType::LittleFS);” generates a compile error – LittleFS storage type seems unknown. So my problem is still there.
Please note I’d prefer to use the old and deprecated ESP32_Mailclient, rather than the new ESP_Mail_Client (both by Mobitz), because the latter takes much more time to send a mail.
Which version of the ESP32 board do you have installed?
Regards,
Sara
I’m using the AI Thinker ESP32-CAM.
Hello, great job! Excellent tutorial.
Is it possible to add code to send an email again once there would be a problem with sending the email for the first time?
Sometimes I am receiving feedback from ESP that it was not able to connect to the server.
The code is working great on ESP32 DEVKITV1 boards. Thanks for the wonderful coding. I do have one ‘issue’. On the serial monitor I get the following message with every email but the emails are sent successfully via gmail account.
“> C: Wait for NTP server time synching”
Connecting to SMTP server…
Error, NTP server time synching timed out
! E: NTP server time synching timed out
this is display in serial monitor, what the happen? pliss
salam sahat, thank rui and sara
Hi.
I found a similar issue here: https://github.com/mobizt/ESP-Mail-Client/issues/247
It seems a problem with your internet connection… I’m not sure.
Either way, can you try a different version of the library?
I use version 2.7.0 and never had that problem.
Go to Sketch > Libraries > Manage Libraries, search for ESP Mail Client, and try to install a different version.
Check if that works with a different version.
Regards,
Sara
Something has changed and broken this tutorial.
I was also receiving the error “! E: NTP server time synching timed out”. When I raised a ticket on Github I was advised to try the example code, I did this and it works just fine.
Clearly, there is a key difference between the library example code and the code on this webpage, what this is I am not remotely clever enough to guess but this webpage code is now giving the error.
I am using an ESP32 DevKitC if that matters.
Hi, I keep running into a LittleFS error with your example and the attachments don’t send with the library example.
the error code I get from your code is:
SPIFFS mounted successfully
Connecting to SMTP server…
Error, NTP server time synching timed out
! E: NTP server time synching timed out
the board I’m using is the TTGO T-Display
Hi.
Replace all “SPIFFS” with “LittleFS” in the code.
Regards,
Sara
Good evening Sara
firt of all, i want to thank you for this tutorial.
Secondly i have the same error and i tried to resolve but nothing.
Please can you help me
=====================Monitor output===========================
Sending Email…
Sending message header…
Sending message body…
Sending attachments…
image.png
text_file.txt
Finishing the message sending…
Closing the session…
Message sent successfully
Message sent success: 1
Message sent failled: 0
Message No: 1
Status: success
Date/Time: 1970/1/1 0:0:14
Recipient: [email protected]
Subject: Test sending Email with attachments and inline images from SD card and Flash
> C: cleaning SSL connection
==============Mail received================================
This message contains attachments: image and text file.
But nothing as attachment
Help !!!!!
Thanks for your tutorial.
but, i have a problem with the attached file my code is:
Attachment Att_SMTP;
att.descr.filename = FileName.c_str();
att.descr.mime = “text/plain”;
att.file.path = FileName.c_str();
att.file.storage_type = esp_mail_file_storage_type_sd;
att.descr.transfer_encoding=Content_Transfer_Encoding::enc_base64;
message.addAttachment(att);
the result is:
/20230414.txt
so I receive the email without an attached file (normal given the result)
In the code I can list the directory and I can list this file.
Do you have an idea
Hi.
That’s some problem with the microSD card.
Double-check that the SD card is properly inserted.
Regards,
Sara
Yes my microSD card is corectly inserted.
During my program, I can list and read all files.
I tryed whith a litle file (75 bytes) same thing….
Is there a specific driver for manged the microSD card adapter?
Hi.
No, there isn’t any specific driver.
Which version of the library are you using?
Regards,
Sara
Hi, this is the version of my job:
|– ESP Mail Client @ 2.7.6
| |– SPI @ 2.0.0
| |– WiFi @ 2.0.0
| |– Ethernet @ 2.0.0
| | |– WiFi @ 2.0.0
| |– LittleFS @ 2.0.0
| | |– FS @ 2.0.0
| |– SD @ 2.0.0
| | |– FS @ 2.0.0
| | |– SPI @ 2.0.0
| |– SD_MMC @ 2.0.0
| | |– FS @ 2.0.0
| |– SPIFFS @ 2.0.0
| | |– FS @ 2.0.0
| |– FS @ 2.0.0
| |– WiFiClientSecure @ 2.0.0
| | |– WiFi @ 2.0.0
|– WiFi @ 2.0.0
Maybe it is a probleme of my SD shield : CATALEX MicroSD card Adapter V1.0 11/01/2013 or ESP32 shield.
Thank you for your help
Hi agian.
Have you tried a sample sketch for your microSD card to make sure everything is working properly?
Regards,
Sara