Using sendmail with gmail oauth2 credentials

I want to send emails programmatically from matlab through gmail, using sendmail. Gmail recently ended support for simple user&password SMTP and they now require oauth2. I almost have oauth2 working, but I think I am stuck on setting up sendmail to properly use "XOAUTH2" credentials. Sendmail returns an error, "Authentication failed."

My question is: assuming I have a valid access token with permissions "scope" set to https://mail.google.com, how do I configure the settings to use sendmail with XOAUTH2?

Any help appreciated, thanks!

[Petorr]

I have set up my smtp environment like this:

setpref('Internet','SMTP_Server',email_server);
setpref('Internet','E_mail',email_address);
setpref('Internet','SMTP_Username',email_user);
setpref('Internet','SMTP_Password',access_token);
props = java.lang.System.getProperties;
props.setProperty('mail.smtp.auth','true');
props.setProperty('mail.smtp.socketFactory.port','587');
props.setProperty('mail.smtp.starttls.enable', 'true' );
props.setProperty('mail.smtp.starttls.required','true');
props.setProperty('mail.smtp.ssl.enable','true')
props.setProperty('mail.smtp.user',email_address);
props.setProperty('mail.smtp.host','smtp.gmail.com');
props.setProperty('mail.smtp.port','587');
props.setProperty('mail.smtp.auth.mechanisms',['XOAUTH2']);

[Petorr]

sendmail error:

Authentication failed.

% more detailed: 

% 'Java exception occurred: 
%      javax.mail.AuthenticationFailedException
%      	at javax.mail.Service.connect(Service.java:306)
%      	at javax.mail.Service.connect(Service.java:156)
%      	at javax.mail.Service.connect(Service.java:105)
%      	at javax.mail.Transport.send0(Transport.java:168)
%      	at javax.mail.Transport.send(Transport.java:98)
%      '

Answer 1

[Jan]

I assume this helps:

https://www.mathworks.com/matlabcentral/answers/1672544-using-gmail-after-may-30-2022

[Petorr]

Yes, I saw that answer and it seems to work so far. I just don't know how long google will support this almost-the-same workaround, if the password expires occasionally or not, etc etc so I was hoping to get the whole oauth2 thing working. The method in the above answer does let me send emails as before, with gmail credentials and sendmail. Thanks Jan!