[118528] in North American Network Operators' Group
Re: ISP port blocking practice
daemon@ATHENA.MIT.EDU (Sean Donelan)
Thu Oct 22 20:39:54 2009
Date: Thu, 22 Oct 2009 20:38:30 -0400 (EDT)
From: Sean Donelan <sean@donelan.com>
To: nanog@nanog.org
In-Reply-To: <4761eff1fe5f8c51a625d6a3396bd4f8@yyc.orthanc.ca>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Thu, 22 Oct 2009, Lyndon Nerenberg (VE6BBM/VE7TFX) wrote:
> My experience is that port 587 isn't used because ISPs block it
> out-of-hand. Or in the case of Rogers in (at least) Vancouver, hijack
> it with a proxy that filters out the AUTH parts of the EHLO response,
> making the whole point of using the submission service ... pointless.
You mentioned this last June. Can anyone else corroborate it? Rogers
says they don't do that, and lots of other people seem to be able to
use port 587 on Rogers (and other ISPs) without problems.
All the cases I've looked at, where someone claimed an ISP was blocking
port 587, it turned out to be some other problem. The most common reason
was related to some security software/host based firewall running on the
user's own computer.
