The upgrade resulted in two short outages.  One server reboot had the mail services down for about 4 minutes.  The actual upgrade and expansion had us down for slightly longer than 15 minutes.  All this was done between the hours of 11pm and 2am (late Sat).  As always, the backup mail servers were online and caught, held and later delivered any emails that might have come through during those times.
 
One of the key additions to our spam prevention arsenal moved out of testing and went live also.  We are now using a product called invURIBL by Invariant Systems.  This amazing tool identifies SPAM by extracting URI's (domain names and IPs in links) from emails and checking them against URI based blacklists. In addition, we have added a unique feature that allows you to check the URI's IP address and remote mail server against Senderbase, the world's leading email traffic monitoring network.  Though we already do a good job at Spam defense, this new technique may catch a few more that otherwise would have slipped through the other spam prevention tools we use (SpamAssassin, etc).
 
The big news on the email services front is that we now support SyncML.  It is no secret we use SmarterMail and this upgrade to 5.5 supports the SyncML protocol allowing any SyncML client to synchronize Contacts, Calendars, Tasks and Notes with devices such as BlackBerry, Windows Mobile, Outlook, iPhone, and Thunderbird, etc.
 
Last but not least, the server itself went from single to dual processor, doubled the RAM and went from a meager 30 GBs of local storage to a massive 300 GB iSCSI RAID5.
 
Thanks - Accuraty/Jeremy