Q: I have messages stuck in my Microsoft Outlook Outbox. What can I do?

A: If you have problems with messages stuck in the Outbox, you can try these actions to fix the problem:

  • Exit and restart Outlook (this often works).
  • Make sure you have network connectivity and that your mail server is available (can you connect to it via web access for example, and does it work from your phone?).
  • Place Outlook in Offline mode, then Online (Select the Send/Receive ribbon and select Work Offline, then after 20 seconds deselect Work Offline).
  • Check that your antivirus supports Outlook and isn't interfering with the moving of messages from the Outbox to Sent (e.g., did you just change your anti-malware solution?).
  • Look at which snap-ins you have enabled and try disabling (File, Options, Add-Ins, Manage COM Add-ins, Go, which allows add-ins to be disabled or removed). For example, I found the Outlook Social Connector 2013 was causing problems for my installation. If disabling a snap-in caused Outlook to hang, that's probably the guilty snap-in, so try the next step.
  • Start Outlook in safe mode
    outlook.exe /safe
    Then try disabling snap-ins, and restart Outlook.