You can’t have two step verification with an Arduino application. You specifically have to follow GMail’s steps for allowing less secure apps access to your account.

Hi.
 
Which project exactly are you trying to follow?
 
We recently updated our tutorials that use Gmail. Gmail requires you to create an app password to allow less secure apps to send emails using your account.
 
Everything is explained in the tutorial. But maybe there are some tutorials that missed the update.
 
This tutorial is updated: https://randomnerdtutorials.com/esp32-send-email-smtp-server-arduino-ide/ See the Create an App Password section.
 
Regards,
Sara
 

Thanks for your replies and the link, now set up using 2 step with app password. Found this when setting up my gmail account :
To help keep your account secure, starting May 30, 2022, ​​Google will no longer support the use of third-party apps or devices which ask you to sign in to your Google Account using only your username and password.
Please note this deadline does not apply to Google Workspace or Google Cloud Identity customers. The enforcement date for these customers will be announced on the Workspace blog at a later date.
For more information, please continue reading.
Special Note on Apple Device Sign-Ins. Users who have not recently signed into their Google Account using only username and password will be able to only make new sign in attempts using the Google account type starting from February 28, 2022. Existing users may continue to sign into their Google Account using their username and password until May 30, 2022.
 
All working now Thank you.

Can someone please tell me if it is possible to use a variable between <h>      </h> as in Hello World!
/*Send HTML message*/
String htmlMsg = “<div style=\”color:#2f4468;\”><h1>Hello World!</h1><p>- Sent from ESP board</p></div>”;
 
many thanks

Hi.
Yes. I think it should be possible to use a variable.
Are you having issues with that?
Regards,
Sara

yes, I need to run the same code about 12 times at different intervals, (could be days) but I feel that programming the same code 12 times just to change the Hello world part, there must be an easier way. I have put the following code in a Void  Sendmessage() and will be calling it in the Void loop section. I am testing the code in the Void loop with a delay. It works as is, sending me an email every 2-3mins but need to change the Re-order Boswellia part.
Hope that makes sense,   many thanks..
void loop(){
  
 
Sendmessage();
 
 
 
 
delay(200000);
}
 
 
void Sendmessage(){
 
 SMTP_Message message;
 ESP_Mail_Session session;
 
  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 = “”;
  
  Serial.print(AUTHOR_EMAIL);
  message.sender.name = “ESP”;
  message.sender.email = AUTHOR_EMAIL;
  message.subject = “Tablet Re-Order”;
  message.addRecipient(“ESP32”, RECIPIENT_EMAIL);
 
  //
 
 String htmlMsg = “<div style=\”color:#2f4468;\”><h1>Re-order Boswellia</h1><p>- Sent from ESP board</p></div>”; 
  
  message.html.content = htmlMsg.c_str();
  message.text.charSet = “us-ascii”;
  message.html.transfer_encoding = Content_Transfer_Encoding::enc_7bit;
  
    if (!smtp.connect(&session))
    return;
  if (!MailClient.sendMail(&smtp, &message))
    Serial.println(“Error sending Email, ” + smtp.errorReason());
}

I just don’t know how to change it to a variable.

Hi. 
I also answered your other question: https://rntlab.com/question/esp32-email/#answer-97033
Yes.
You should concatenate your existing string htmlMsg with the variable.
For example:
String yourVariable;
String htmlMsg = “<div style=\”color:#2f4468;\”><h1>" + YourVariable +"</h1><p>- Sent from ESP board</p></div>”;
To learn more about string concatenation, you can read this arduino guide: https://docs.arduino.cc/built-in-examples/strings/StringAdditionOperator.

If you want to use a function, you need to pass the text you want to send as an argument. You need to declare your function as follows:
void Sendmessage(String variable){
(…)
Then, concatenate that variable with the existing HTML variable:

String htmlMsg = “<div style=\”color:#2f4468;\”><h1>" + variable +"</h1><p>- Sent from ESP board</p></div>”;

Then, when you want to send messages, simply call Sendmessage() and set as argument the message. For example:
 

Sendmessage("Re-order Boswellia");

I hope this helps.
 
Regards,
Sara

You can also take a look at this project that creates a function to send emails.

ESP32 Email Alert Based on Temperature Threshold (change values on web server)