Whenever I am on my home wifi network, I can rarely access email messages from my Google Apps account. It is set up as an IMAP account, and almost 100% of the time when I receive a new message it says "Message ______ not available on the server." These messages are there if I get on the web, and I never have this problem outside of my home network. I tried forwarding the IMAP port, but that did not help.

Do you know what could be causing this problem?

Thanks