We have an accounts payable account that is solely used for receiving invoices from customers. The account is not generally logged onto, instead the AP personnel are delegates for that email account and access it from their own outlook. I received an email from a delegate stating that the account is no longer receiving external emails. We recently deployed Office 2007, and Symantec Mail Security for Exchange 6.x, but that was about a month before the last external email was received. Only the one account has reported this problem. What could have happened, and how can I troubleshoot this?