One Exchange user not recieving external email

One of my users (ME) can receive any internal email, but cannot receive any email from outside.
This just recently started. The senders are getting a variety of messages but most common is a that my mailbox is full. I have cleaned it out
its around 4mb right now.
Everyone else is receiving email fine. It is setup so that a copy of all emails from everyone in the company gets forwarded to the boss, and she is receiving her copies of my emails.

Any Ideas?