AOL blocking MailScanner messages!

Matt Kettler mkettler at EVI-INC.COM
Thu Dec 4 02:02:31 GMT 2003

At 08:46 PM 12/3/2003, Jeff A. Earickson wrote:
>    Are you guys talking about the "accept_unresolvable_domains" mc setting
>in sendmail?  As of version 8.9, sendmail won't accept email from unresolvable
>domains unless this feature is defined.  I've never enabled it at my site
>after sendmail 8.9 (a while ago), and I've never had any complaints about it.
>Or is there some other setting to reject sites lacking RDNS?

accept_unresolvable_domains has to do with being able to find a MX for the
envelope's From: address..

Some distros (ie: older redhat) ship with accpet_unresolvable_domains
enabled, I disabled it, hence my comment that I reject unresolvable from's

However, this has nothing to do with RDNS at all, and nothing to do with
what AOL is doing. AOL is implementing refusal of mail from servers that do
not have a reverse DNS lookup for their IP. It's not rocket science to do
in sendmail, i.e. something like this:

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