Using classic Outlook for Windows in business environments
For classic Outlook for Windows, start with the least disruptive fix:
- In Outlook, go to Send/Receive > Work Offline.
- Open Outbox.
- Delete the stuck message, or move it to Drafts.
- Turn Work Offline off.
- Send a new test message.
If the message still cannot be removed, the mailbox folders may be out of sync or corrupted. Reset the Outlook folders:
- Exit Outlook.
- Press Windows + R.
- Run:
Outlook.exe /resetfolders
If the issue continues, reset the default folder names:
- Exit Outlook.
- Sign in to Outlook Web App.
- Go to Settings > Options > General > Region and time zone.
- Change the language, select the date and time format, select Rename default folders so their names match the specified language, and save.
- If the preferred language is already selected, switch to another language, save, then switch back and save again.
- Restart Outlook.
If Outlook shows no message in Outbox but still keeps trying to send one, use MFCMAPI to remove the hidden stuck item. Warning: this includes a permanent delete step.
- Close Outlook.
- Install the MFCMAPI tool.
- Open MFCMAPI and select OK.
- Select Session > Logon.
- Select the Outlook profile and choose OK.
- Double-click the affected account.
- Right-click Root Mailbox > Open contents table.
- Check columns such as From, To, and Subject.
- If a message with subject Read appears, select it, then choose Actions > Submit > Abort submit.
- Right-click Delete message and choose Permanent delete passing DELETE_HARD_DELETE (unrecoverable).
- Restart Outlook and test send/receive again.