When my users are away from the office, their active sync email (Exchange 2003) works fine on their smart phones/tablets. In the office, they have to shut off their wireless lan connection on their cell before it will work. Only works through cellular connection.
Here's what I THINK is going on:
It's a DNS issue. Outside email address is going to mail.companyname.com. Inside the domain is company.local. Wireless doesn't know how to get to mail.companyname.com from the inside.
I think I need to create a new zone (is this possible on an SBS2003 box?) and point the outside address to the NATted inside server, like mail.companyname.com = 192.168.1.50 or something similar.
Does this sound right? What else could it be?