I keep seeing this type of alert email every now and then. What is it?
I've censored out my users domain and my servers domain.
Received From: s1->/var/log/psa/maillog
Rule: 1002 fired (level 2) -> "Unknown problem somewhere in the system."
Portion of the log(s):
Nov 11 22:58:46 s1 qmail-scanner: Clear:RC:0(18.104.22.168):SA:0(-2.1/5.0): 0.728626 4749 email@example.com nigel@[removed].com Username_Error <007e01cb81f3$f9a70620$ecf51260$@firstname.lastname@example.org> 1289516325.30711-1.s1.[removed - my server].net:2699 1289516325.30711-0.s1.[removed - my server].net:161 orig-s1.[removed - my server].net128951632579030709:4749
Is this anything to be worried about, or is it a bounced email? My users email address does exist as an alias of his email account.
I don't get loads of these sort of emails a day, but they do come in, around 3 a day every other day.