To everyone else reading this... I have worked for about an hour with
Moshe on this, we got around it by cheating and just using his universities IMAP server instead. It looks like his university uses an expired SSL certificate which despite forcing trust on it, it just isn't working.
To answer your question, I first need to say it isn't possible to connect mail to OWA (well, old versions used it for public folders, but, that's another story). What you want to do is connect mail to Exchange.
Outlook Web Access is just the name for the Exchange web interface, and, you do not connect applications to it.
If you easily set it up on iOS, this was most likely down to choosing
Exchange as the server type.
The latest version of OSX's Mail does have support for Microsoft Exchange 2010 now, and I am unsure as to why you are having problems.
All I can suggest is that you make sure your server type is set to Exchange and you set the settings correctly.
Just Googled for a picture, please again, double check that you did set the Exchange mode, it should look something like this: