I had an issue here recently where after moving mailboxes from Exchange 2003 to Exchange 2007 and then to a new Exchange 2007 server, a user’s Inbox folders disappeared from their mailboxes. All other folders were still there (Calendar, Tasks, Sent Items, other ‘mail’ folders), just the Inbox was missing.

The view through Outlook Web Access (OWA) was much the same. Re-creating the offline sync file (*.ost) had no affect. Starting Outlook with “outlook.exe /resetfolders” also had no impact.

The KB924226 - Contacts or other default folder hidden, but shortcut works with Open in New Window seems to be a similar problem.

Workarounds
  • Can still access inbox from the Outlook today page.
  • Can still access from mobile device
  • Right-click ‘Mailbox’ | Open Other Folder | Open Other User’s folder | type the user name.
Solution
  1. Download mfcmapi from this link: http://www.microsoft.com/downloads/details.aspx?FamilyID=55fdffd7-1878-4637-9808-1e21abb3ae37&displaylang=en
  2. Extract this on the end-user’s computer having the issue
  3. Open up MFCMapi on the computer and choose the “Session” then “Logon and Display Store Table”.
  4. Select the profile that the user uses to access email then double-click the “Mailbox MDB” 
  5. On the new folder that opens, expand “Root – Mailbox” and then expand the Information Store folder which will show all the folders in the mailbox (IPM_SUBTREE)
  6. Highlight Inbox
  7. On the right pane, look for the Property Name – “PR_ATTR_HIDDEN”. This should have a tag of 0×10F4000B. Under the Value column, this should be set to False by default. 
  8. If it is set to True, right-click this Property Name, then, select “Edit Property”
  9. Uncheck the checkbox, which sets the attribute to F (False) and click on OK.
  10. Refresh the screen by selecting F5 and make sure that the change did not revert back to T (True).
  11. Close MFCMapi.
  12. Open Outlook and see if Inbox folder is now showing in the Mailbox Hierarchy.
Cause

If it was experienced some time after the mailbox move (which it was), then it has nothing to do with the move. Something must be changing the property bit. This could be a 3rd party product such as Anti-Virus software or an Outlook Add-in