We wanted to move our email off of our network so that even if we had a severe outage, we would be able to communicate with our customers. Rackspace email hosting is great. We've currently got 7 mailboxes at $2/month each, and plan to use Rackspace for any future email hosting needs. The webmail interface is good (not as good as others but still good enough for a quick access here and there). But where the Rackspace email really excels is the IMAP/SMTP works very quickly and reliably. Took two days to provision in the system, but supposedly that was a one-time issue caused by website maintenance and several different factors. Not a major problem, and since being deployed the email hosting is great.