SMTP error received when setting up a new SMTP connection

Problem Statement:

We set up a new SMTP connection. Users are not receiving Auth0 emails or receive the below error:

"error": "Invalid login sequence while waiting for \"334 VXNlcm5hbWU6\": 500 Syntax error, AUTH command unrecognized"


Please review the SMTP Provider’s settings or logs. The Email provider’s documentation can also help.