[Mimedefang] MIMEDefang as a mail gateway...?

Les Mikesell les at futuresource.com
Fri Mar 5 16:43:22 EST 2004


On Fri, 2004-03-05 at 15:00, Jason Williams wrote:

> I'm setting up a mail gateway server for our company that is going to have 
> the following:
> 
> FreeBSD 4.9
> Sendmail 8.12.11
> Latest versionof MIMEDefang
> 
> Sole purpose is to scan all incoming mails for the company, clean them, 
> then pass them off to the internal mail server.
> 
> I wanted to know if there maybe any potential problems with this particular 
> setup? Anything I should be aware of before I begin testing and setting up.
> 

The only real problem is that if the outside gateway is unaware of
legitimate user names it will accept everything, then when the
inside mailer rejects the unknown users the outside box must
construct and return the bounce message.  If you are tagging spam
instead of rejecting it and the company has many ex-employees that
have their addresses on spam lists you can end up with a big
outgoing queue of junk you are trying to return to unreachable
addresses.

The best solution here is probably to put the users in LDAP and
configure the outside mailer to use it but I haven't done that
myself yet.  I just periodically grep the logs for the rejections
and stick the frequent ones into sendmail's access list with a
REJECT on the outside machine. 

---
  Les Mikesell
   les at futuresource.com




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