Likely fix
Fix: Outlook not sending emails
Outlook usually fails to send when it is offline, a message is stuck in the outbox, the attachment is too large, the account password changed, or SMTP/account settings are wrong.
Quick answer
Check Work Offline mode, clear the outbox, remove large attachments, restart Outlook, and make sure the account can sign in.
Important warning
If one stuck email blocks Outlook, copy the message text somewhere safe before deleting it from the outbox.
Try this
- 1 Check that your internet connection works.
- 2 In Outlook, make sure Work Offline is not enabled.
- 3 Open the Outbox and look for stuck messages.
- 4 Remove large attachments or create a new simple test email.
- 5 Restart Outlook.
- 6 Restart the computer.
- 7 Check whether Outlook asks for your password.
- 8 If using custom domain email, check outgoing server or SMTP settings.
Common causes
Work Offline mode is enabled.
Stuck message in the outbox.
Large attachment.
Account password changed.
SMTP settings are wrong.
Outlook profile is corrupted.
What to check next
- Check whether Work Offline is enabled.
- Check the Outbox.
- Check whether a simple email sends.
- Check whether Outlook asks for a password.
- Check whether webmail can send from the same account.