Outgoing mail blocked - 5.7.0 error

[debandburke]

Our outgoing mail has been stuck in the outbox for over a week - this error is appearing:

[SMTP]Cannot send message ('From' field address 'debandburke@tpg.com.au' not accepted due to the following reason:
"5.7.0 Authentication required
")

Please advise, thanks

[david64]

Hi @debandburke . Do you have "SMTP authentication" set for outgoing mail? The article has instructions for Outlook, Windows mail and Mac mail.

https://community.tpg.com.au/t5/Broadband-Internet/How-to-enable-SMTP-Authentication/m-p/91825#M3547....

PS. I don't know why it should suddenly be different.