[sendmail] help with backscatter

[Andrzej Adam Filip]

Chris Harms <chris at cmiware.com> writes:
> We are having some trouble with our servers sending out backscatter
> spam.  I realize this is really a Sendmail issue, but if any list
> readers have some insights on the best way to make Sendmail stop
> sending bounces to outside domains, it would be greatly appreciated.

Make sendmail reject messages to non existing cyrus mailboxes in reply
to "RCPT TO:" command in SMTP session. It makes host sending you the
message responsible for generating bounce message.

Take a look at solutions described at
 http://anfi.homeunix.net/sendmail/#cyrus
* I suggest "Cyrus Aliases" in virtusertable or aliases for small sites
  or sites with stable list of user mailboxes.
* Otherwise consider deploying "Real Time Cyrus Integration Version 2".
  (RTCyrus2).

P.S.
RTCyrus3 is under development 
 http://groups-beta.google.com/group/cyrus-sendmail
Testers are welcomed.

-- 
[pl2en: Andrew] Andrzej Adam Filip : anfi at priv.onet.pl : anfi at xl.wp.pl
Home site: http://anfi.homesite.net/