WP Mail SMTP by WP Forms is the plugin I use for my site for email service. Recently I changed my Gmail password and my email stopped working, giving me “Token has been expired or revoked”. So here is the quick solution to make it working again with Google SMTP.
Here is the screenshot of the error I got:
What you need to do is disconnect WP SMTP connection from Gmail and reconnect it. It will start working again.
Here is some screenshot if you don’t know how to do it: