In this day in age, set up a hotmail or gmail account, and use that for non-work correspondence.... I get too many people in trouble at work when I am asked to view their emails and monitor for non-work related stuff.
Most companies have software running on their mail server that will use wildcards to block email. ( I.E. if the email contains certain keywords or is from certain sites, it will block it. )
There is often times no way around this, unless you are the server admin, because it is something controlled centrally.
If you need a gmail invite, plenty of us will hook you up, else opt for another free email service and use that.