Re: Is your ISP blocking outgoing port 25?

["J.D. Falk" <jdfalk-lists () cybernothing org>]

Joe Provo wrote:
> On Thu, Jun 18, 2009 at 03:36:44PM -0400, Zhiyun Qian wrote:
> > It has been long heard that many ISPs block outgoing port 25 for the purpose
> > of reducing spam originated from their network.
>
> Yes, it is standard practice for non-server accounts and most dynamic-only
> accounts; only allow unauthenticated smtp traffic to your own smtp servers.
> If you are not running server-to-server traffic at the end of that broadband
> pipe, then you should be shifting your userbase to authenticated on the SUBMIT
> port [587] anyway...

The Messaging Anti-Abuse Working Group (MAAWG) published recommendations for 
managing port 25 traffic a few years ago, and even then it had already been 
a widely-accepted best practice for nearly a decade.

http://www.maawg.org/port25

--
J.D. Falk
Return Path Inc
http://www.returnpath.net/