Currently Being ModeratedJul 29, 2012 5:40 AM (in response to geordiskywalker)
I am facing a -perhaps- similar issue. I upgraded to Mountain Lion a couple of days ago, and today I tried to upgrade my Mac Mini Server (didn't work, issues with the external disk which contains the user folders). However, as long as the server was down (it's my mail server), Mail CPU consumption was up to 100%. As soon as the server was restored and powered up the CPU consumption went down to the normal levels.
Currently Being ModeratedJul 30, 2012 8:40 AM (in response to John Caradimas)
I think this is similar, it works on the basis that the server isn't available (for one reason or another) and the mail app is constantly trying to get to it. I wonder if Apple is aware of this, or if it's just environmental.