With so many applications to access email; mobile and installable client there is always a chance for things to go wrong. Two of the main problems I see are data duplication and data purges of calendar and contact items. Using built-in Deleted Item Retention of Microsoft Exchange you can recover those lost items with ease using a Microsoft Outlook client. Prior to Outlook 2010 you could add a registry key to your computer to enable the use of Recover Deleted Items from any folder in your mailbox, including non-mail items folders. However if your using Outlook 2010 you will not find the Recover Deleted Items button when you click on a non-mail items folder, whether you have the registry key or not. Using the instructions below you can add the Recover Deleted Items icon to the Folder section of your Ribbon for all folders regardless of the data they contain.
The Recover Deleted Items icon is in the Folder section when you are in a mail item folder.
When you are viewing a non-mail item folder (calendar, contacts, etc…) the Recover Deleted Items icon is no longer available. If the contact “Mr. John J Doe” was Shift-Deleted or purged by your mobile client (I have seen it more times than I can count) how would you get it back?
With Outlook 2010 open click the File Ribbon tab then click the Options button.
On the right-hand side add a New Group under the Folder main tab. You can rename it after it is created.
Change the “Choose commands from:” to All Commands. Scroll down and select the “Recover Deleted Items…” option then click the “Add > >” button to add this option to your newly created custom group.

You will now see your new group and the Recover Deleted Items icon in the Folder tab on all folders.

If you were to click the button you will see that you have access to any purged/shift-deleted items from that folder.

If you use the recover option you will see that your item has now been returned.

This test was done using Appriver's Hosted Exchange 2007 backend product. There are new changes in Deleted Item Retention with Microsoft Exchange 2010 and we will document them as soon as Microsoft releases their new Hosted version of Exchange 2010. If you have any questions/comments please let feel free to leave them in the comments section.
- James Dean
Senior Exchange Engineer, AppRiver LLC
Exchange Hosting by AppRiver
Life saving!
Hello,
I have unitentionally deleted my emails in Outlook 2010.
The "Recover Deleted Items" is "unabled", can you help me how to enable the "Recover Deleted Items"?
I appreciate very much you kind help in this case.
Kind regards,
Suryana
Cheers and Thanks for taking the time to screen shot this.
David
http://www.1callservice.com