"Someone managed to hack in by brute force anyway. I only
noticed because of the _millions_ of automated replies that were coming in every day from dead email accounts or people
that were out of office."
This is not a description of your email server being cracked. It's a description of someone Joe-jobbing pretending to send mail from your domain. Duckgo for mitigation techniques..
In fairness, there's not enough information provided to determine which this is, though my suspicion is that OP wouldn't know the difference regardless.
This is not a description of your email server being cracked. It's a description of someone Joe-jobbing pretending to send mail from your domain. Duckgo for mitigation techniques..