Sophos XG ISP changed and built-in email server to send Backup externally stopped working

Did you use a smtp relay from the previous ISP?

That rings a bell (I set this up quite a while

ago).

Please let us know if this is the solution.

What do I need to change, where?

Email > General settings > Smarthost settings

If there is a relay host defined, and it is related to the previous ISP change this.

In between, I received a quarantined digest of a 'blocked' email!!!

I believe its because I need to add the new IP address in the SPF settings for domain.

I'll let you know after the week-end once changed.

Thank you