Items are missing from your mailbox when you use Outlook to connect to Exchange Online

When you use Microsoft Office Outlook 2007, Microsoft Outlook 2010, or Microsoft Outlook 2013 to connect Microsoft Exchange Online in Microsoft Office 365, you notice that some messages are missing from the mailbox.�

Typically, this issue may occur if one or more of the following conditions are true:

• The message was deleted.
• The message was archived.
• Outlook is set up to use a custom view that may be filtering the missing message.
• The missing items weren't synchronized to your Outlook profile.

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:To resolve this issue, use one or more of the following methods.�

Method 1: Search for the missing items

Search Outlook for the missing item

Open Outlook, and then use the Outlook search feature to manually check the following locations for the deleted items:�

• Inbox
• Deleted items
• A folder where the message previously existed
• A specific folder
• A mailbox-level search

Search Outlook Web App for the missing item

1. Sign in to the Office 365 portal (http://portal.microsoftonline.com).
2. Click Outlook.
3. Search for missing items by using the search bar in the middle of the page.

Method 2: Increase�how much mail�is stored locally

Outlook 2013 lets users determine how much data they want to store locally. You can increase�how much data you're storing in your Offline Folder file (OST). For more info about how to change�how much mail to keep offline, go to the following Microsoft website:

Method 3: Recover messages that were deleted

Recover a message that was deleted from the Deleted Items folder

1. In Outlook, click the folder that contained the missing message, such as the Inbox folder, the Deleted Items folder, or a specific folder in which the message previously existed.
2. On the Folder tab, in the Clean Up group, click Recover Deleted Items.
3. In the Recover Deleted Items dialog box, select the missing message from the list, and then click the Recover Selected Items button.

Recover a message after a hard-delete or when the Deleted Items folder is empty

1. On the computer that you're using to perform the deleted items recovery operation, click Start, click Run, type regedit, and then click OK.
2. Expand the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Exchange\Client\Options

   
   
   Note If part of this registry subkey doesn't exist, it must be created manually.
3. Right-click Options, point to New, and then click DWORD Value.
4. Type DumpsterAlwaysOn, and then press Enter to name the new value.
5. Double-click DumpsterAlwaysOn.
6. Type 1 in the Value data box, click Decimal in the Base area, and then click OK.
7. Exit Registry Editor.
8. Restart Outlook.�
9. Select the folder from which the message was deleted, or select the folder in which the message existed before the message disappeared.
10. Do one of the following:
    • In Outlook 2007: On the Tools menu, click Recover Deleted Items.
    • In Outlook 2010: On the Folder tab, in the Clean Up group, click Recover Deleted Items.
11. In the Recover Deleted Items dialog box, select the missing message from the list, and then click�Recover Selected Items.

Method 4: Search archived folders

The AutoArchive feature can be set up in Outlook to store mail data. These rules can be used to move messages automatically to separate local folders. You can search the archived folders, disable the archive, and move the data back into the primary OST file. For more info about how to use the AutoArchive feature, see the following Microsoft Knowledge Base article:

Method 5: Remove custom views�or filters in Outlook�

Sign in to your Exchange Online mailbox by using Outlook Web App. If you can see the message in Outlook Web App, Outlook might be using a custom view and filter. To remove the filter, follow these steps:

• If you're running Outlook 2007, follow these steps:
  1. Click View, select Current View, and then click Customize Current View.
  2. In the Customize Current View dialog box, click Filter.
  3. In the Filter dialog box, click Clear All to remove the current filter, and then click OK.
• If you're running Outlook 2013 or Outlook 2010, click the�View tab, and then in the Current View group, click Reset.

Method 6: Check whether a retention policy is applied in Outlook

Retention policies can be applied by Exchange Online admins across an organization, or they can be applied by users in Outlook 2010. To determine whether a retention policy is applied in Outlook, follow these steps:

1. Open Outlook, right-click the folder where the messages should have been delivered, and then click Properties.
2. Click the Policy tab.
3. In the Folder Policy box, note whether the option that's set is anything other than Use Parent Folder Policy.

To determine whether a retention policy is defined, repeat these steps for all parent folders in the path. If a policy is defined, work with an Exchange Online admin to remove the policy, if it's necessary.

Still need help? Go to the Office 365 Community website.