Meetings appear in the calendar as Tentative but the user didn't receive the requests in the inbox or meeting responses from others don't appear in the inbox

We have had several calls recently. Majority of them are Mac Outlook 2016 users (we are running Exchange 2016). We found out solution 1 of the MS KB https://support.microsoft.com/en-us/kb/2966790 fixed the issues

 Users experience one or both the following symptoms in Outlook:

• The user doesn't receive meeting requests in their inbox. However, the meetings appear in the user's calendar as Tentative.
• When the user creates a meeting request, the user doesn't see meeting responses from attendees. However, tracking information for the meeting is updated in the user's calendar.

In this scenario, the user does not have a delegate set up.

CAUSE

This issue occurs if the meeting requests were processed incorrectly in the user's mailbox and they get delivered to the user's Deleted Items folder instead of the Inbox folder or the meeting requests were processed incorrectly as if a delegate was set up. 

This can occur if the Receive folder for the IPM.SCHEDULE.MEETING message class was changed to the /Schedule folder or if the PR_RULE_MSG_PROVIDER property of messages that have as message class of IPM.Rule.Version2.Message is set to Schedule+ EMS Interface.

SOLUTION

To resolve this issue, start by following the steps in Solution 1. Depending on the scenario, you may have to use the steps in Solution 2. You will not know which solution applies to the user until you start troubleshooting by using the steps in Solution 1. 

Note The exact steps will vary based on the version of the MFCMAPI tool that you're using. Use caution when you modify mailboxes by using MFCMAPI. Using this tool incorrectly can cause permanent damage to a mailbox.

Solution 1

1. Download MFCMAPI from http://mfcmapi.codeplex.com/.
2. Start MFCMAPI.
3. On the Session menu, click Logon.
4. Select the user's online mode Outlook profile, and then click OK.
   
   Note If the user doesn't have an online mode profile, create a profile. Or, on the Tools menu, click Options, and then make sure that both the Use the MBD_ONLINE flag when calling OpenMsgStore check box and the Use the MAPI_NO_CACHE flag when calling OpenEntry check box are selected.
5. In the list, double-click the user's primary mailbox.
6. In the new window that appears, on the MDB menu, point to Display, and then click Receive folder table.
7. In the window, look for IPM.SCHEDULE.MEETING. Then, do one of the following:
   • If IPM.SCHEDULE.MEETING is not present, go to Solution 2. 
   • If IPM.SCHEDULE.MEETING is present, go to step 8 of this procedure.
8. Expand the Root container.
9. Right-click Schedule, click Advanced, and then click Set Receive Folder.
10. Enter IPM.SCHEDULE.MEETING in the box.
11. Click Delete Association, and then click OK.
12. Repeat step 6 and 7 to make sure that the IPM.SCHEDULE.MEETING association is removed from the list.
13. Test to see whether the user can receive meeting responses and meeting requests in their inbox.

Solution 2

1. Download MFCMAPI from http://mfcmapi.codeplex.com/.
2. Start MFCMAPI.
3. On the Session menu, click Logon.
4. Select the user's online mode Outlook profile, and then click OK.
   
   Note If the user doesn't have an online mode profile, create a profile. Or, on the Tools menu, click Options, and then make sure that both the Use the MBD_ONLINE flag when calling OpenMsgStore check box and the Use the MAPI_NO_CACHE flag when calling OpenEntry check box are selected.
5. In the list, double-click the user's primary mailbox.
6. Expand the Root container, and then expand Top of Information Store.
7. Right-click Inbox, and then click Open Associated Contents Table.
8. In the upper part of the window, scroll to locate the Message Class column.
9. Click Message Class to sort the Message Class column.
10. Look for all messages that have a message class of IPM.Rule.Version2.Message.
11. Click each message that has a message class of IPM.Rule.Version2.Message, and then in the lower part of the window, look for a property that's called PR_RULE_MSG_PROVIDER.
12. Check whether the PR_RULE_MSG_PROVIDER property has a value of Schedule+ EMS Interface.
13. In the upper part of the window, delete messages whose PR_RULE_MSG_PROVIDER property have a value of Schedule+ EMS Interface.
14. Test to see whether the user can receive meeting responses and meeting requests in their inbox.