While Windows Mobile 6.5 and Windows Mobile 6.5.3 came with a couple of Microsoft Exchange Server 2010 enhancements, these enhancements weren't available for Windows Mobile 6.1 phones. However, Microsoft has recently released an "Office Outlook Mobile" update for the use of Microsoft Exchange Server 2010. With the update, Windows Mobile 6.1 users can benefit from some of the new features - including grouped E-Mails by conversation, improved free/busy lookup and the ability to sync SMS text messages. The Outlook Mobile update is available for all Windows Mobile 6.1 Professional (with touchscreen) and Standard (without touchscreen) smartphones.
E-Mails Grouped by Conversation: With your E-Mails grouped by conversation, you can quickly see all responses and perform common E-Mail actions that apply to the entire conversation, such as deleting, replying, flagging, and moving E-Mails.
Free/Busy Lookup: Getting in touch with people in your organization is now more effective with calendar availability. Have a quick question that needs to be answered? Quickly check a colleague's schedule to determine if a face-to-face visit in their office or a phone call is possible, or send them an E-Mail if their schedule is booked.
Enhanced Voice Mail: Exchange Server 2010 Unified Messaging provides voice mail preview, giving you a text version of your voice mail messages so you can read them without having to call and listen to each.
Sync SMS Text Messages to Exchange: SMS messages now appear inside of Outlook or Outlook Web Access, so you don't need to pull your phone out of your pocket to read and respond when you're sitting at your PC. You can even get your SMS text messages if you forgot your phone at home right from within Outlook or Outlook Web Access.
The update isn't distributed as a separate cab download (not to mention the use of Microsoft's Windows Mobile update functionality) but when your phone is connected to an Exchange Server 2010, you are automatically informed that there's an update available. Users of Windows phones running Windows Mobile 6.5 or Windows Mobile_6.5.3 don't need this update at all.
Cheers ~ Arne