How to deal with pending messages

If you send an email and Outlook shows that there are pending message, but none of them is in the Outbox folder. The messages cannot be sent and progress bar is stuck. The problem is in message requesting read receipt in TNEF format. Outlook generates a reply with the same format. If TNEF is disabled by Outlook Sync, reply message remains stuck in the Outbox until it is deleted by the .pst editor or TNEF is enabled again.

Figure. Outbox.

To send out pending emails, enable TNEF:

1. Go to Outlook Sync Settings -> Advanced tab and uncheck Disable TNEF.

2. Go to Outlook Options -> Mail -> scroll to Tracking and set Never send a read receipt .

3. Go to Outlook Sync Settings -> Appearance tab and check Handle read receipts. Set handling to your preferences (Always send, Never send, Ask before sending).

4. Restart Outlook.

5. Click Send/Receive button to send all ending read receipts.

6. Go to Outlook Sync Settings -> Advanced tab and check Disable TNEF.

7. Restart Outlook.