There are a large number of viruses floating around the system. Don't open any email messages with large attachments coming from my account. In fact, the most straightforward thing is not to open any attachment at all unless you know for a fact that it was being sent to you specifically. The current viruses are nasty and they use email addresses that look like people you may know and they even take subject lines you may have used or received. So they look legit, but they are NOT!
Delete them immediately without opening them.
Senior Library Specialist