Missing emails and mailbox folders - issues with shared mailboxes (Exchange & Outlook 2010)

Here are some interesting examples of problems with missing or misplaced emails that happen when multiple users share a mailbox (e.g. assistant/manager or multiple users/service mailbox).

User A manages mailbox B. Mailbox B is attached to Outlook of user A, and user A has full access to mailbox B, that is, can send messages as user B and can delete messages from mailbox B.

When user A sends emails from user B's mailbox, the copies of these emails are stored in user A’s sent items, but not in user B’s sent items.

When user A deletes messages from mailbox B, these messages end up in user A’s deleted items folder, instead of in user B’s deleted items folder.

Sometimes, users who manage someone else’s mailbox accidentally move emails and/or folders to their own mailboxes. Then others with similar access wonder what happened to these emails and folders.

Here is how to ensure that sent and deleted emails are always stored in the owner’s mailbox. These new values need to be set up for each mailbox delegate and can be deployed through GPO.


Deleted items:

• For Outlook 2013
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Options\General

• For Outlook 2010
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Options\General

• For Outlook 2007
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Options\General

• For Outlook 2003
HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Options\General

• For Outlook 2002
HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Options\General

• For Outlook 2000
HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Outlook\Options\General

Right-click the DelegateWastebasketStyle value, and then click Modify.

If the key is not present, use the following steps to create it:

a. Right-click the General folder in the path that is defined in step 4 in the "To Switch the Destination of Deleted Items" section earlier in this article.
b. Point to New, and then click DWORD Value.
c. Type DelegateWastebasketStyle, and then press Enter.

Change the value data in the Edit DWORD Value dialog box to one of the following values:

8 = Stores deleted items in your folder.
4 = Stores deleted items in the mailbox owner's folder.

Sent (as) items:

Key: HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Preferences
Name: DelegateSentItemsStyle
Type: DWORD
Value: 1

If users report missing emails and/or folders, these can be located through the Discovery feature (Multi-Mailbox Search) of Exchange Control Panel.

Go to https://cas-server/ecp/ and log in as admin or a user with the permission to run Multi-Mailbox Search. Go to Mail Control > Discovery. Click on New to open a New Mailbox Search wizard window. Here, set up filtering using one or more of the following:

Email/subject keyword(s)
Sender/recipient email address
Date range (from-to)
Mailboxes to search

For example, if emails are missing from a mailbox 123, and there are 7 different users who have access and manage the mailbox, then all these 7 mailboxes need to be searched.

The last section of the new search wizard is: Search Name, Type and Storage Location. Here set the name of the search (this will be the name of the folder with the results), select “Copy the search…”, remove the tick mark from Enable deduplication, select Enable full logging, and if the mailbox is not selected, select the Discovery Search Mailbox. Click Save and periodically click the refresh button. Once completed, the Status will change to Search Succeeded and the Size will show the size of the search results. If Size shows 0 B, it means the search didn't find anything, so you need to change the filtering parameters and re-run the search.

To see the results in your Outlook, grant yourself full access to the Discovery mailbox, and it will pop up in your Outlook after a while. The results of the search will appear as a new folder. If the folder cannot be expanded, just collapse the Discovery mailbox and expand it again, then check the folder again.

If the emails were moved or deleted to another user’s mailbox, there will be a subfolder with that user name (as a mailbox) followed by subfolders (the name of the search > username > Inbox > xyz folder > etc).

Here is an example:

A user reported a subfolder with all its messages missing from a common shared mailbox. The user provided the subject of one of the messages that were stored in the missing subfolder and the date range when the message was received, so I searched for the message in all the mailboxes that were granted full access and send as permissions over the shared mailbox, and found that one of the delegates moved the entire folder to her own Inbox. The search result looked like this:

The resulting folder structure helps to locate the messages and folders that contain these messages. The reading (right) pane lists the messages.

More info:

Email that you send on behalf of someone is not saved in their Sent Items folder
Give Users Access to Multi-Mailbox Search
Items that are deleted from a shared mailbox go to the wrong folder in Outlook
Messages that are sent by using the "Send As" and "Send on behalf" permissions are copied only to the Sent Items folder of the sender in an Exchange Server 2010 environment
Save Sent Items in owner’s mailbox