So, when things are seemingly broken with Exchange connectivity from the Internet, where do we turn?
The Microsoft Exchange Remote Connectivity Analyzer:
There is, however, a very important security caveat when it comes to some of the connectivity tests:
Do you see it?
Yes, there is a requirement for a domain username and password!
So, when it comes to testing certain types of connectivity to Exchange, we need to set up a temporary username and password and once we are done delete that account.
Other than that _small_ caveat, the tool is very helpful! ;)
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book