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.