Can send but can't receive email in Outlook 2007

I am unable to receive messages in Outlook 2007. I can send without issue, but I cannot receive across a variety of email addresses with various port settings. Outlook was working without any issues until a few days ago and there were not any updates or installations that can be linked to this issue. I have tried removing the antivirus software entirely and I have disabled the firewall but still can’t receive messages. I do however receive emails on my blackberry from all email accounts. I have verified settings with my domain hosting company. When clicking on the “Test Account Settings” button on the “Internet E-mail Settings” page Outlook does not detect any issues however the test email is only received on the blackberry and not in Outlook. Outlook also does not show any errors when attempting to send and receive emails. Thanks for your help on this baffling problem.
I am using: Outlook 2007, XP Pro, Lenovo T61p