www.simplymailsolutions.com
Hosted Exchange - Exchange hosting provider www.simplymailsolutions.com now has virtuozzo for vps and websites at the best prices in the UK! Exchange and zimbra mailboxes, zimbra desktop already supported! as well as POP3 IMAP SMTP boxes from £1 a month.
Best Hosted Email provider in the UK in my biased opinion 
and one of the few that properly support apple MacOSX, Go take a look!