Delete message from Outbox

I have a message stuck in my Outbox (because it is to large to send). I tried to delete it but I get the following error;

“Can’t open this item. The MAPI Spooler has already begun transmitting this message.”

How can I get rid of this message?

There are a couple of techniques to get rid of such a stuck message. The solution that works for most is the following;

1. Place Outlook in Offline Mode via File-> Work Offline
2. Close Outlook.
3. Verify in Task Manager (CTRL+SHIFT+ESC) that the outlook.exe process is no longer listed on the Processes tab.
4. Start Outlook again.
5. Double click the message in Outbox to open it in its own window.
6. Either delete it, move it to the Drafts folder or remove its attachments and send it again.
7. Put Outlook back on-line by disabling File-> Work Offline
8. Press the Send/Receive button.

If this doesn’t work for you, there are some alternative methods described in this guide.

Note 1: To prevent this from happening again, you can create a rule which monitors if your not sending messages which are too large.

Note 2: If the message that is stuck in your Outbox is a Read Receipt, the above methods will not work as outgoing Read Receipts are invisible for the Outbox. You can follow the instructions posted here instead to get rid of a stuck Read Receipt.