As far as I can tell PM does indeed continue to check mail in user account 'A' even whilst fast-switched to user account 'B'. I have a 2nd account on my machine for my girlfriend to use and often when she's logged into her side of things I hear PM chime to alert me to new mail on my side (she uses web-based email, so I know that the chime isn't coming from her user account).
Useful! Rick -- G5 2GHz x2 :: 2GB RAM :: 10.3.1 :: PM 4.2.1 :: 3 pane mode -- Original message: Received from Mark Smith on 9/1/04 at 7:09 am >I have just upgraded my 700MHz iMac to OS X 10.3. Apart from the changes >Apple appears to have introduced to the way permissions and ownerships >are handled all has gone well. > >The performance of PM (4.2.1) is definitely better than it was under >10.2.x, especially tasks such as compacting the database etc., are >noticeably quicker. It also appears that PM continues to check mail on an >account, if you use fast user switching to switch to another user ID. Is >this correct, or is it just ultra-fast when you log back into to the >previous account? (Sometimes the volume of new mail seems to be too much >for PM to be accessing mail as the previous ID rotates into view again.)