Are app passwords needed for gmail SMTP and, if so, when did that start?

Question

In July 2019, I used gmail's SMTP settings along with username and password for sending email in a project. This worked fine when I tested it in July 2019.

This might not be important detail but I used PHPMailer and PHP in the project.

From my activity logs in the project, it appears to stop working by January 2020.

I got it working again after setting up 2 step authentication and switching the project to use an app password.

Are app passwords needed now for gmail SMTP and if so, when exactly did that start?

Answer 1

Thanks, codemonkey.

codemonkey, how do you know it was working in July 2020? Are you sure you tested it properly in July 2020?

I'm not completely sure the email failed in January 2020 but something did. I can see in logs that users were trying to use a Google Calendar scheduling feature repeatedly in January as if they were running into a problem. Fixing the email fixed the entire feature now which is why I strongly suspect emailing to be the problem back then too. The feature also reads and writes events on a Google Calendar but authenticating that has always been using a token instead of a password.