Hi Faith,
I see you upgraded from Build 8601 to Build 8629. This shouldn't have caused any user conversions, reindexes or the like, so I'm afraid the high CPU/RAM is unexplained at this point. Is this problem still occurring? Or has it since resolved?
If you're still seeing spikes, please open a support ticket so we can help to assist you. If the spikes have stopped and you have a backup of your SmarterMail installation from before your upgrade, you can still start a ticket as well. If you can provide the backup, we can stage it locally and see if this behavior can be reproduced.
Kind regards,
Andrea Free
SmarterTools Inc.
877-357-6278
www.smartertools.com