This guide helps resolve an email error of type "535 5.7.0 authentication failed".

Resolve an Authentication failed error

The mail authentication service on the servers may encounter an issue for a few brief seconds exceptionally, during unusual events on the infrastructure for example.

If an error 535 5.7.0 authentication failed occurs:

• Try sending the email again and it should go through.

If the problem persists, check the points in this other guide.