Outlook Not Sending Emails Fix (Step-by-Step Guide)

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Outlook Not Sending Emails Fix is usually needed when Microsoft Outlook is unable to send messages, even though it appears to be working normally. This issue can delay communication and cause frustration.

In this guide, you’ll learn simple step-by-step solutions to fix Outlook sending issues and restore normal email functionality.

Why Is Outlook Not Sending Emails?

If Outlook is not sending emails, it is usually caused by connection issues, incorrect settings, or account-related problems.

This issue can appear as emails stuck in the Outbox, sending errors, or messages failing to deliver.

What Causes Outlook Not Sending Emails?

  • No internet connection
  • Outlook set to Work Offline
  • Incorrect SMTP settings
  • Large attachments
  • Corrupted Outlook profile
  • Email server issues

How to Fix Outlook Not Sending Emails

Try the following solutions one by one until Outlook sends emails properly.

Check Internet Connection

Outlook needs an active internet connection to send emails.

  1. Open a browser
  2. Try visiting a website
  3. If it does not load, restart your router
  4. Reconnect to the internet
  5. Try sending the email again

Make Sure Outlook Is Not Set to Work Offline

If Outlook is set to Work Offline, it will not connect to the internet or send emails.

  1. Open Outlook
  2. Look at the top menu and click the Send/Receive tab
  3. Find the Work Offline button
  4. It may appear highlighted or pressed
  5. If it is highlighted: Click Work Offline once to turn it OFF
  6. Look at the bottom of the Outlook window (status bar)
  7. Check if it says “Working Offline”
  8. If the message disappears, Outlook is now online
  9. Try sending your email again

Check the Outbox Folder

Emails stuck in the Outbox can prevent new messages from being sent.

  1. Open Outlook
  2. Look at the left panel (where Inbox and Sent Items are listed)
  3. Click Outbox
  4. If you do NOT see Outbox:
  5. Click the small arrow to expand folders
  6. Or scroll down in the folder list
  7. Look for emails that are stuck
  8. These are messages that have not been sent
  9. Click one of the stuck emails to open it
  10. Check for problems:
    • large attachments
    • incomplete email address
    • missing subject or content
  11. Fix any issues (remove attachments if needed)
  12. Click Send again
  13. If the email still does not send:
    • delete the message
    • create a new email
    • try sending again

Reduce Email Attachment Size

Large attachments can prevent Outlook from sending emails.

  1. Open Outlook
  2. Go to the Outbox folder
  3. Open the email that is not sending
  4. Look for attached files – These appear below the subject line
  5. If the file is large:
    • right-click the attachment
    • click Remove Attachment
  6. Save or close the email
  7. If you still need to send the file:
    • compress it into a ZIP file
    • OR upload it to a cloud service (like Google Drive or OneDrive)
    • send the download link instead
  8. Click Send again

Check Email Account Settings (SMTP)

Incorrect outgoing server settings can prevent Outlook from sending emails.

  1. Open Outlook
  2. Click File (top-left corner)
  3. Click Account Settings, then click Account Settings again
  4. In the window that opens:
    • select your email account
    • click Change
  5. Check the following details carefully:
    • Email Address → must be correct
    • Incoming mail server (IMAP/POP)
    • Outgoing mail server (SMTP)
    • Username → usually your full email address
    • Password → re-enter it to make sure it is correct
  6. Click More Settings
  7. Go to the Outgoing Server tab
  8. Make sure: “My outgoing server (SMTP) requires authentication” is checked
  9. Click OK, then click Next
  10. Outlook will test your settings
  11. Wait for the test to complete
  12. If the test fails:
    • double-check your email details
    • search online for your provider’s SMTP settings
    • or contact your email provider
  13. Click Finish
  14. Restart Outlook
  15. Try sending your email again

Make sure the correct SMTP port is used (commonly 587 for TLS or 465 for SSL, depending on your provider).

Restart Outlook

Restarting can fix temporary issues affecting email sending.

  1. Close Outlook
  2. Wait a few seconds
  3. Open Outlook again
  4. Try sending email

Repair Outlook

Repairing Outlook can fix underlying issues.

  1. Open Control Panel
  2. Go to Programs → Programs and Features
  3. Select Microsoft Office
  4. Click Change
  5. Choose Quick Repair
  6. Follow instructions

Check Antivirus or Firewall Settings

Security software can sometimes block outgoing email connections.

  1. Temporarily disable antivirus or firewall
  2. Try sending an email
  3. If it works, re-enable protection
  4. Add Outlook as an exception

How to Prevent Outlook Sending Issues

  • Keep Outlook updated
  • Avoid large attachments
  • Maintain stable internet connection
  • Check settings regularly

Frequently Asked Questions

Why are my emails stuck in Outbox?

This is usually caused by connection issues or large attachments.

Can I fix sending issues myself?

Yes, most issues can be resolved with basic troubleshooting steps.

Is this a serious issue?

No, it is usually easy to fix.

You may also want to check our guides on Outlook Not Working Fix, Outlook Not Receiving Emails Fix, Outlook Search Not Working Fix and Outlook Not Opening Fix for related issues.