Exchange Hosting from GASP.net
http://www.gasp.uk.net/

Exchange 2003 Hosting from LanLogic
http://www.lanlogic.net/exchange/2003-shared.asp

USA.NET Hosted Email Solutions for SMB’s
http://www.usa.net/solutions/exchange.html

Hosted Exchange 2003 by myOfficeSystem
http://www.myofficesystem.co.uk/services/hostedexchange.asp

Microsoft Exchange Hosting at Final ASP
http://www.finalasp.com/exchangehosting.html

Elephant Outlook Exchange Hosting 2003
http://www.elephantoutlook.com/

Microsoft Exchange by ZDI
http://www.zidar.com/managed/exchange/index.htm

Hosting Exchange 2003 with DSLExtreme
https://secure.dslextreme.com/medusa/exchange/

Hosted Exchange by Virtual-eMail
http://www.virtual-email.net/index.htm

Microsoft Exchange Hosting from Mi8
http://www.mi8.com/Services/Hosted_Exchange.htm