The problem you're having isn't wrapping, per se, it's a difference between the way text is wrapped on the Mac (Mail and Entourage, for sure) and Windows (any Outlook related program, most Webmail applications, etc.). Those links will be clickable on a Mac. Some or all of the wrapping is likely to be taking place at the receiving end, anyway.
To get them clickable even if you send them to a Windows user, try somehting like
TinyURL
Good luck
srb