I got hit by this yesterday. I run a postfix server with a spamcop check and email stopped coming through. I had fail2ban setup to shut out bad SMTP requests and interestingly this spamcop issue made fail2ban completely ban the incoming SMTP requests.
Thankfully I figured that part of it out, but it is nice to see where the issue actually came from.
Thankfully I figured that part of it out, but it is nice to see where the issue actually came from.
[I took out spamcop checks completely.]