SMTP unable to log into Microsoft 365

Support
1

Just started receiving this error for the SMTP Email:
The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 Client not authenticated to send mail. Error: 535 5.7.139 Authentication unsuccessful, the request did not meet the criteria to be authenticated successfully.

I have added an App Password, also reset the main password. I’ve added the QuickFile IP address so as not to request MFA. None of which seem to work… Any suggestions?

2

Hi @Q6IT

Sorry to hear you’re having issues with the SMTP.

We don’t do anything special with this, it’s just a connection using the settings saved on your account.

Providing the server, username and password are all correct, I’d double check the port and the STARTTLS setting (usually, this is enabled for providers like Microsoft 365).

If you’re still seeing an error, it may be worth querying this with your email provider to see if they can provide any more details.