North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: Why do so few mail providers support Port 587?

  • From: Eric A. Hall
  • Date: Fri Feb 25 12:14:49 2005

On 2/25/2005 10:51 AM, Nils Ketelsen wrote:

> On Thu, Feb 24, 2005 at 11:36:40PM -0500, [email protected] wrote:
> I force anyone, who wants to relay to use SMTP-AUTH on port 25. Only mails
> for local delivery are accepted without AUTH. Whats point
> in opening another port? 

There are lots of secondary benefits. One of my favorites is that I can
reject mail session on port 25 from hosts that claim to be in my domain
(all such mail is authenticated on port 587 or is coming from a
pre-configured list of servers that already hit an exception, so any other
connections on port 25 that HELO as are lying). There are lots
of these kinds of non-trivial benefits.

Eric A. Hall                              
Internet Core Protocols