On my iPhone (4), I can set up my company e-mail, which allows me to receive and send e-mail and use the calender to manage appointments. The company is using Exchange 2003.
The problem is that this is the only way I can access my e-mail when I'm not at the office. I've tried setting up an account on Outlook 2007, Outlook 2010, Outlook 2011 (Mac) and the OSX Mail app, but it doesn't work. The server cannot be reached, even though I've used the exact same settings as on the iPhone.
The info I use on the iPhone is:
Server name of the company mail server (it's the same as for webmail)
Use SSL
AD Domain of my account
My AD account name
Password
When I enter this on the iPhone, it works like a charm, but whatever I try on one of my desktops, it doesn't work.
FYI: I can't ask the company IT guys because according to them, it doesn't work from a remote location, not even on the iPhone (but obviously, that works just fine)