My university is forcing it’s students to have an account with Windows Live email service in order to get the university announcements/updates. Today I noticed a very strange behavior, in certain situations the website doesn’t let you configure email forward to another account outside of the Microsoft network. The following error message is shown:
You can forward your mail to one other e-mail address that ends in hotmail.com, msn.com, live.com, or is part of Windows Live Custom Domains.
I’m using Iceweasel 3.0.11 from Debian, and I complained about missing that feature, other people seemed to have the feature. After a few checks it’s seems to be the way the browser identify itself. When I changed my identification to IE7/Vista (using user agent switcher plugin), the problem was solved.
I’m trying to understand the logic – If i use IE or Firefox, I can do a forward to another account, but otherwise I’m locked in to the Microsoft network. It can’t be a technical issue, as in both cases the interface is the same (no special browser features needed).
Free Software Universe 
It’s a common problem. One of the best known Polish universities has an admission webapp supporting Firefox but not Iceweasel.
Properly designed software uses the user agent identification only for statistics. JavaScript allows simple determination of what specific features are provided by the browser. In CSS and HTML unknown features are ignored. Only the ignorance of web app developers lead to such problems.
What makes me wonder is if the withhold of the option is a logic error, or intended.
You should forward it to the Opera guys, they have sued Microsoft for that kind of issues before.
I second that one. Get the Opera guys involved.
It’s not that they block you by purpose, they just use bad browser detection code.