sendmail FEATURE(`accept_unresolvable_domains') : What do you do?

[Steven E. Protter]

As most of you know in my past work I always commented this feature out of my sendmail configuration.

Now however, I'm running sendmail on set of corporate gateway servers that process all incoming mail.

We do not have this feature commented out and therefore accept mail that includes unresolvable domains.

I'd like to know what your policy is on this and if when activating this feature on inbound mail gateways there was any adverse impact.

5 points per response since its a survey. Throw in some advice or gotcha's to avoid and perhaps achive bunny status.

SEP

[Geoff Wild]

Policy is simple - do not accept unresolvable domains - both where I work (day job) and my part time hosting company.

I'm also (as you helped) using the require_rdns" HACK and that is working great! Cut down at least 75% of the spam hitting my server.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=991392

On the corporate side - we also use some sort of mail filtering server which strips and block incoming mail with certain attachements (like java script, exe's, zips, etc). I believe it's Windows based - so I don't know much about it (can find out if you like).

Rgds...Geoff

[Ivan Ferreira]

Unresolvable domains normally does not send usefull information. We also have as default policy to not allow unresolvable domains. No complains received.

[Chan 007]

SEP,

I thing the sendmail 8.9 has something for you.

http://www.sendmail.org/tips/relaying.html

Overhere we accept all unresolved domains. No one questions that, as they are not TECKIEs...!!!

Regards
Chan