AOL blocking MailScanner messages!

Jeff A. Earickson jaearick at COLBY.EDU
Thu Dec 4 01:46:07 GMT 2003

   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?

We have a lot of users with Adelphia broadband at home, and Adelphia is
notoriously bad about no RDNS for their cable modems.  Since we run
tcpwrappers in paranoid mode, I see lots of remote connections from Adelphia
to our academic system rejected by tcpwrappers.  Still, almost no
complaints from our users.  Maybe they are just timid.

--- Jeff Earickson
    Colby College

On Wed, 3 Dec 2003, Matt Kettler wrote:

> Date: Wed, 3 Dec 2003 19:55:52 -0500
> From: Matt Kettler <mkettler at EVI-INC.COM>
> Reply-To: MailScanner mailing list <MAILSCANNER at JISCMAIL.AC.UK>
> Subject: Re: AOL blocking MailScanner messages!
> At 07:16 PM 12/3/2003, you wrote:
> >It's a shame other admins don't do this, however I do support AOL on this
> >move
> As do I.. Hopefully it will at least cause _some_ of the lazy network
> admins out there to get off their butts and set up their reverse DNS zones.
> Unfortunately, right now there's an awful lot of admins that VERY bad about
> getting their butts in gear and making RDNS entires. I can't afford to
> bounce email just because the system admin of the other site is lazy,
> incompetent, or just massively understaffed and not getting the time to do
> it all.
> (note that said ineffective admin isn't always the same as the admin of the
> affected mailserver, but there's always SOMEONE who should be responsible
> for the RDNS that isn't getting the job done).
> I do however require a MX for the Mail From: address.. I figure if they
> don't have that much, nobody can reply to them anyway. It occasionally
> delays mail with DNS server outages, but no biggie, it's a 4xx error so it
> gets retried.

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