Ok... Sorry it has been awhile since I started this. I originally posted this at the beginning of the month. I missed my window. I had to allow another couple of weekends go by because; 1) had to go to a conference in Vegas for a week & 2) had to fix the hardware issue. Yes, it turned out to be a bad memory card.
Zimbra has now been in production for this past work week. I hear grumblings about not having Outlook because I am forcing them all to use the web and they don't have R/D receipts, but this has really cleared up the spam/viruses. I'll stick with it for awhile.