up vote 2 down vote favorite
share [g+] share [fb]

When configuring a mail server, what is the best practice for rejecting an inbound internet email with an executable type I'd like to disallow? Easiest option is an NDR/DSN, but I'd think that could put one at risk to create backscatter.

link|improve this question
serverfault.com/q/329162 – quanta Nov 25 '11 at 19:24
feedback

1 Answer

up vote 3 down vote

When the mail server is sendmail, I install MIMEDefang use it to enforce attachment policy.

link|improve this answer
3  
...which is especially useful since it is a so-called "milter" and allows for real-time filtering. This way, the mail server simply would send a reject response upon reception of the DATA section - NDRs would be someone else's problem then. Sendmail is not the only mailserver to support this, Postfix' before-queue content filters will do the same. – syneticon-dj Nov 25 '11 at 21:17
Thanks guys. I read that many MTAs won't honor a reject code like 550 during the DATA section of the conversation, which is concerning. – Ode Nov 29 '11 at 15:55
feedback

Your Answer

 
or
required, but never shown
discard

Not the answer you're looking for? Browse other questions tagged or ask your own question.