You can't view mailbox folders on an Exchange ActiveSync or Outlook client after an IMAP migration

Original KB number:   3050475


You can't view one or more folders in a user's mailbox on a Microsoft Exchange ActiveSync client or in Microsoft Outlook after the user's mailbox is migrated from an Internet Mail Access Protocol (IMAP) messaging system to Microsoft 365 or on-premises Microsoft Exchange Server.


This issue occurs if the folders in the Exchange mailbox were created by using an unrecognized class of type IPF.Imap. An analysis of the folder properties shows the following results:

<property tag = "0x3613001E" type = "PT_STRING8">
<ExactNames>PR_CONTAINER_CLASS, PR_CONTAINER_CLASS_A, ptagContainerClass</ExactNames>
<PartialNames>PR_CONTAINER_CLASS_W, PidTagContainerClass</PartialNames>
<AltValue>cb: 8 lpb: 4950462E496D6170</AltValue>


Use Microsoft Exchange Server MAPI Editor (MFCMAPI) to change the PR_CONTAINER_CLASS property of the folder to IPF.Note. To do this, follow these steps.


Although the MFCMAPI editor is supported, you should use caution when you use this tool to change mailboxes. Using the MFCMAPI editor incorrectly can cause permanent damage to a mailbox.

  1. Download MFCMAPI, and then run it.
  2. On the Tools menu, select Options.
  3. Select the Use the MDB_ONLINE flag when calling OpenMsgStore check box and the Use the MAPI_NO_CACHE flag when calling OpenEntry check box.
  4. On the Session menu, select Logon.
  5. Select the Outlook profile for the mailbox.
  6. Double-click the mailbox to open it.
  7. Expand the Root container, expand Top of Information Store, and then locate the missing folder.
  8. Select the folder that's missing from the Exchange ActiveSync client to view the properties.
  9. Double-click the property that contains the tag value 0x3613001E.
  10. Change the value from IPF.Imap to the appropriate class. (For example, change the value to IPF.Note for an email folder.)
  11. Exit MFCMAPI.
  12. Create a profile on the Exchange ActiveSync client.