[Avcheck] kavkeeper + "User unknown"

[Michael Tokarev]

George Chelidze wrote:
> Hello,
> 
> I am using KAV as AV software + kavkeeper. The MTA is sendmail-8.12.9. 
> Lately I have noticed (didn't pay attantion to this before) the 
> following problem:
> 
> say geo.net.ge is local domain.
> 
> without main injection mechanism activated, issuing
> 
> RCPT TO: userdoesnotexsist@geo.net.ge
> 
> I get:
> 
> 550 5.1.1 userdoesnotexsist@geo.net.ge... User unknown
> 
> after enabling injection mechanism I get:
> 
> 250 2.1.5 userdoesnotexsist@geo.net.ge... Recipient ok
> 
> At this level message is collected. Only the LDA (procmail in my case) 
> rejects it with "User unknown". As the result many useless messages are 
> wasting my bandwidth.

This is a general problem with sendmail+virusscanner, where scanner
is plugged using "reinjection" mechanism.  This problem can't be
solved without hacking sendmail's code.  But sendmail has general
content-filtering mechanism called "milter", and there are some
programs that can talk with kaspersky's KAV and to sendmail via
milter.  If you're using Sendmail, please find appropriate solution
that utilizes milter API.

BTW, avcheck suffers from the same problem.

/mjt