Outlook Web Access

First, I can’t log on to the outlook web access if I include the EXTENSION. Example,
http://ooakinsolaofchicago.com/exchange is not permitted but if I removed the exchange I am allowed to procide a spot where I can then type the exchange and be allowed in.

Second, At work I am allowed to log on using Josh Stone and not jstone but at home I am allowed to log on using jstone and not Josh Stone.

What could be the problem? Do I need to delete all the accounts and re-enter them or there is a way to do this without re-entering the names and accounts?