[Mimedefang] Aggressive mailers

[Jonas Eckerman]

Hello!

I've been thinking about getting my filter to blacklist (for a month or so) mailers that can't take no for an answer, but yesterday something happened that made me wanna check with others first.

Yesterday a mailer went amok when trying to get a mail through to our server. It was tempfailed by the greylist as it should, but instead of waiting for awhile before trying again it retried 886 times in 10 minutes (after witch it was let though by the greylist).

At first I thought this had to be some kind of virus or spam, but I turned out to be a legitimate* mail to a user. Not only that, it came from a server handled by an ISP that rents mail services to other companies (and therefore really should know better).

My question is:

Do you people often see otherwise acceptable mailers exhibiting this kind of behaviour? I can take having to lecture other admins** before our users get their mail as long is it isn't too often.

I haven't seen any legitimate mail comming at us like this before, so I suspect it's pretty unusual.

*: Ok, the mail wasn't really perfectly legitimate. It wasdeclared as multipart, but it didn't contain any "parts" at all except the default part that is shown for non MIME-capable clients. That part contained badly formated and completely pointless HTML. But it was legitimate in that the user actually wanted it, and had even asked for it.

**: Yes, of course I have written to postmaster (both the ISP's and the domain's) about it. Haven't received any answer yet though.

Regards
/Jonas

-- 
Jonas Eckerman, jonas at truls.org
http://www.truls.org/