MailScanner as mail proxy

[Marc Lucke]

Hi list,

I know this is getting off topic.  I know enough about sendmail to be 
99% sure that this question should be on their list.  But any help, 
ideas or feedback would be welcome.  I'm guessing the MailScanner 
community would have come across my problem on more than 1 occasion.

I run MailScanner on a remote machine to my actual mailserver.  In other 
words all mail is relayed via the Mailscanner box.  This is to stop 
viruses and spam on the mailserver I have to run which is very limited 
in such defenses.  It all works great, apart from one annoying problem:  
if someone sends to an unknown email account (as oft occurs) the 
MailScanner proxy (for want of a better way to describe it as I'm using 
it) first accepts the email, attempts delivery, cannot deliver and then 
tries to notify the sender who doesn't exist.  So I'm lumbered with a 
billion postmaster non-delivery emails.  I'm keeping up with this quite 
well, but I'm scared I'll miss a legitimate message because it's buried 
in garbage.

Is there anything I can do to get anything in MailScanner to check with 
my destination email server that the actual account exists before 
accepting the email in the first place?


Marc