Tips for Using SMTP On the Road

It is becoming increasingly difficult to send email when on the road. Most email relies on a service called Simple Mail Transport Protocol (SMTP). To prevent misuse by spammers, many servers and networks place restrictions on SMTP. When this occurs you may be able to download new mail to your inbox, but the messages you send will generate an error and remain unsent.

SMTP typically uses port 25 for communication with the server. Simple SMTP has no authentication or other protection against abuse. The good news is that you can turn on password authentication (gatorlink at UF) and encryption (aka SSL) to greatly enhance security. Many servers will let you use SMTP without restrictions as long as you can prove who you are by authenticating. If you use a password you should also use encryption so that nobody can intercept and steal your credentials. That's all well and good, but these measures won't make a difference if port 25 is blocked somewhere along the way.

One solution to this problem is to use a VPN to 'tunnel' back into your 'home' network (where the mail server lives). Authentication and encryption are generally not required since you are seen as local on the network. Unfortunately the current campus VPN does not play well with OSX 10.4. <frown>

But all is not lost! Another technique is to change SMTP to use port 587. This port has been reserved for "safe" (ie, authenticated) mail submission. It is likely to gradually supplant port 25. In Apple Mail, go to the Accounts preference pane, select or enter the smtp.ufl.edu host name and click Server Settings.... Enter 587 as the server port. (Also set up password authentication and SSL if you haven't done so already.) I've tested this from a hotel wireless connection, and it appears to clean things up nicely. Plus, you should be able to 'set and forget' these settings. They should still work when you return to your 'home' network. <smile>

Prepared by Richard Rathe :: May 26, 2006 :: MedMac Users Group