[118518] in North American Network Operators' Group
Re: ISP port blocking practice
daemon@ATHENA.MIT.EDU (Lyndon Nerenberg (VE6BBM/VE7TFX))
Thu Oct 22 19:15:36 2009
To: justin@justinshore.com
From: "Lyndon Nerenberg (VE6BBM/VE7TFX)" <lyndon@orthanc.ca>
Date: Thu, 22 Oct 2009 17:14:11 -0600
In-Reply-To: <4AE0DF32.1040903@justinshore.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
> Few
> companies use the MSP port (tcp/587).
Can you elaborate. Is this based on analysis you've conducted on
your own network? And if so, is the data (anonymized) available for
the rest of us to look at?
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.
--lyndon
