I'm getting 10K+ frozen messages and I'm wondering if there is a way I can
prevent this from happening.
I have a backup MX host, called mx1, which relays to all my customer domains.
The spammers (as we all know) like to use MX-spam techniques to relay mail
through mx1 to my customer's mail servers.
Lately, I've seen dictionary-like MX-spam attacks.
adam@???
bill@???
carrie@???
....
....
Exim, on mx1, will happily try to delivery the message to the customer mail
server. Most of the message get "User Unknown", which bounces back to mx1 and
gets frozen.
We I think I'd like to do is receipient verification(?) of the envelope?
Something like, mx-spam comes into mx1 for adam@???, exim on mx1
callsout(?) to mail.company.com and tries to verify adam, if "User Unknown"
is the return value, mx1 would error 5xx the mx-spam.
Is this possible?
--
Bob Tanner <tanner@???> | Phone : (952)943-8700
http://www.mn-linux.org, Minnesota, Linux | Fax : (952)943-8500
Key fingerprint = AB15 0BDF BCDE 4369 5B42 1973 7CF1 A709 2CC1 B288
