It can be frustrating when emails don’t send properly in Outlook. If your emails are automatically sent to the Outbox, there are a few steps that you can take to try and resolve this issue:

1. Check Outlook for any disabled add-ins.
2. Check your Outbox for any stuck messages that need to be sent.
3. Check the size of the attachment. If it’s too large, delete it or reduce its size before attempting to send it again.
4. Reset your Outlook data file.
5. Check for any unsent messages in the account’s Sent folder.