Why do so few mail providers support Port 587?

Fri Feb 25 04:36:40 UTC 2005

On Thu, 24 Feb 2005 17:14:17 EST, Jim Popovitch said:
> 
> If supporting one port is y hours of time and headache, then two ports
> is closer to y*2 than y (some might argue y-squared).  587 has some
> validity for providers of roaming services, but who else?  Why not
> implement 587 behavior (auth from the outside coming in, and accept all
> where destin == this system) on 25 and leave the rest alone?

Well, OK.  If you know for a *fact* that your users *never* roam, and you
have sufficiently good control of your IP addresses that you can always safely
decide if a given connection is "inside" or "outside" and allow them to relay
based on that, then no, you don't need to support 587.

The rest of us run mail services in the real world, where lots of users buy
laptops, and then actually <gasp, shock> *use* the portability and thus often
end up behind some other ISP's port-25 block.
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