Len: No it's not. Redirecting port 587 to port 25 will by definition involve an outside (the firewall) IP address due to the firewall not being part of an internal communication (probably not true if you are running some sort of port-remapper on the IMail box itself).
With relay off for all external addresses, port 587 becomes submission ONLY. Yes, it will accept non-Authenticated email for local users, but no more so than port 25. No [New] exposure there. It will relay for Authenticated users, and can be routed by most ISPs, and so does provide the desired functionality. I know, that's how I'm configured here. Ideal configuration: 587 SMTP-AUTH only, local or relay. 25 SMTP local, no relay; SMTP-AUTH local or relay. Actual configuration (with the firewall mapping External 587 to 25): 587 SMTP local, no relay; SMTP-AUTH local or relay. 25 SMTP local, no relay; SMTP-AUTH local or relay. No difference in functionality. The only difference I can see is if a Spammer is sending the same junk to both interfaces, you'd get the Spams twice. But, SpamAssassin (http://www.visioncomm.net/sac) is killing both copies. MAYBE there's a performance hit there, but I don't worry about that too much. SpamAssassin is batting way over 990 here, and I'm quite happy with it. So's my buddy running his Blackberry mail through SpamAssassin - He's Ecstatic! Dan Barker > port 587 requiring SMTP AUTH needs no anti-spam defense. (Imail can't do > this. Re-directing port 587 to port 25 is just port 25 service) > > Len To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
