[Mimedefang] Spam to inactive accounts

[Les Mikesell]

>From: "Jeff Grossman" <jeff at stikman.com>

> Doesn't Sendmail tell the sending server that the account doesn't exist
> during the SMTP Transaction stage?  That would mean the message never
> really makes it to your machine.  So, there should not be a bounce
> message.  The bounce message should be created by the machine sending
> you the invalid message.

You see this problem when you have a relay host on the internet that
forwards to one or more internal mail servers that may be behind
a firewall.  The relay accepts everything for the domain(s) without
knowing about users, then gets the error when forwarding to the
internal server.   The worst part about it is that the relay will then
try to bounce the error back to the sender which is usually unreachable.
I've been periodically grepping through the relay maillog for the
addresses rejected by the internal servers, then putting them in
the access file to reject on the relay.    It would probably be better
to put all the users and aliases into an LDAP directory that all
the machines could see.

   Les Mikesell
    les at futuresource.com