Here is a quick overview of our setup:
Domain hosted by Earthlink along with our POP3 email, DSL with Verizon (now a static IP), have our own Small Business Server 2003 w/ Exchange 2003. I originally had the server setup with an SMTP connector to forward to outgoing.verizon.net using basic authentication w/ our Verizon username and password.
It worked great for several months. Then one day it stopped and we started getting authentication required errors. Verizon, due to increasing volumes of relayed spam they were tighting down on relays and we would need a static IP to fix the problem. (Took them 3 weeks to set it up) This temporarly fixed it. But this past Friday I started getting errors. After talking to Verizon they said it looked like my username and password was being entered wrong, but I haven't changed it since I originally set it up. Any ideas?