If Microsoft Outlook will not send emails, the solution might be as simple as changing a setting. However, it could also be something a bit more complicated. Walking through common troubleshooting steps can help you fix Outlook not sending emails.

How to Fix Outlook Not Sending Emails in Outlook 2019 and 2016

Resend the Message

Sometimes trying to send an email again does the trick.

These instructions apply to Outlook 2019, 2016; Outlook for Mac 2016 or Outlook for Mac 2011; and Outlook Online.

  • Right-click the email stuck in the outbox, point to Move and choose the Drafts folder.
  • Open the email in the Drafts folder and click Send.
  • Check to see if the message is now in the Sent folder or still in the outbox.

Double-check Recipient’s Email

A tiny typo—such as a comma instead of a period—prevent Outlook from sending an email.

Right-click the email stuck in the outbox, point to Move and choose the Drafts folder.

Open the email in the Drafts folder and click Send.

Check to see if the message is now in the Sent folder or still in the outbox.

Check Your Connection

Verify you are connected to the internet then ensure you’re working online in Outlook.

  • Look at the lower-right corner of the Outlook window. If it says Disconnected, Working Offline, or Trying to connect, you are not connected to your email server.
  • Click the Send/Receive tab on the ribbon.
  • Click Work Offline in the Preferences group. You should now see Connected to Server in the lower-right corner of the window.
  • Click the Send/Receive All Folders button in the Send & Receive group.
  • Check to see if the message is now in the Sent folder or still in the outbox.

Look at Attachments

Outlook limits the size of files you can send to 20 megabytes for internet accounts, such as Gmail or Hotmail, and 10 MB for Exchange accounts. If you receive an error message about the file size when you attempt to send an email, increase the Outlook attachment size limit.

Look at the lower-right corner of the Outlook window. If it says Disconnected, Working Offline, or Trying to connect, you are not connected to your email server.

Click the Send/Receive tab on the ribbon.

Click Work Offline in the Preferences group. You should now see Connected to Server in the lower-right corner of the window.

Click the Send/Receive All Folders button in the Send & Receive group.

Sync Your Password

If you have recently changed your email password online, you must change it in Outlook as well or you won’t be able to send (or receive) emails.

  • Click File > Account Settings > Account Settings.
  • Select the Email tab.
  • Choose your email account and click Change.
  • Enter your updated password in the Password box.
  • Select Next > Close > Finish.
  • Select the Send/Receive All Folders button in the upper-left corner of the Outlook window or press F9 to try sending your email.

Repair Outlook

It’s possible your Outlook application is damaged. Use the built-in Microsoft Office repair utility to fix it.

Click File > Account Settings > Account Settings.

Select the Email tab.

Choose your email account and click Change.

Enter your updated password in the Password box.

Select Next > Close > Finish.

Select the Send/Receive All Folders button in the upper-left corner of the Outlook window or press F9 to try sending your email.

Repair Outlook 2016, 2013 or 2010 in Windows 10

  • Close all Microsoft Office applications.
  • Type Apps & Features into the Windows search box.
  • Select Apps & Features.
  • Find and click on Microsoft Office in the list of installed apps and features.
  • Select Modify > Yes if a user account control window appears asking, “Do you want to allow this app to make changes to your device?”
  • Select Online Repair > Repair.
  • Restart Outlook when the repair process is complete.

Repair Outlook 2016, 2013 or 2010 in Windows 8

  • Close all Microsoft Office applications.
  • Right-click the Start button.
  • Select Control Panel.
  • Make sure Category is selected in the View By list.
  • Click Uninstall a Program under Programs.
  • Right-click Microsoft Office and choose Change.
  • Select Online Repair if it is available (this depends on the type of Microsoft Office you have installed).
  • Click Repair > Yes if a user account control window appears.
  • Restart Outlook when the repair process is complete.

Repair Outlook 2016, 2013 or 2010 in Windows 7

  • Close all Microsoft Office applications.
  • Click the Start button > Control Panel.
  • Make sure Category is selected in the View By list.
  • Click Uninstall a Program under Programs.
  • Select Microsoft Office from your list of programs.
  • Click Change > Online Repair if it is available (this depends on the type of Microsoft Office you have installed).
  • Click Repair > Yes if a user account control window appears.
  • Restart Outlook when the repair process is complete.

Fix Outlook Not Sending Emails in Outlook for Mac 2016

In the Mac version of Outlook, there are a few things you can try to get Outlook working again.

Close all Microsoft Office applications.

Type Apps & Features into the Windows search box.

Select Apps & Features.

Find and click on Microsoft Office in the list of installed apps and features.

Select Modify > Yes if a user account control window appears asking, “Do you want to allow this app to make changes to your device?”

Select Online Repair > Repair.

Restart Outlook when the repair process is complete.

Right-click the Start button.

Select Control Panel.

Make sure Category is selected in the View By list.

Click Uninstall a Program under Programs.

Right-click Microsoft Office and choose Change.

Select Online Repair if it is available (this depends on the type of Microsoft Office you have installed).

Click Repair > Yes if a user account control window appears.

Click the Start button > Control Panel.

Select Microsoft Office from your list of programs.

Click Change > Online Repair if it is available (this depends on the type of Microsoft Office you have installed).

A tiny typo, such as a comma instead of a period, can prevent Outlook from sending an email.

First, make sure you are connected to the internet. Once you have confirmed your connection, make sure you are working online in Outlook. To do so, go to the Outlook menu, check to see if Work Offline is selected. If so, click Work Offline to remove the check mark and work online.

Empty the Send Folder

Empty the folder to clear “stuck” messages. Any message you delete must be re-created—it cannot be recovered or undeleted.

  • Open the Send folder.
  • Delete all of the messages in the folder.
  • Quit Outlook.
  • Restart Outlook.
  • Try sending an email to see if the issue is resolved.

Rebuild the Outlook Database

Using the Microsoft utility to rebuild a corrupted database might fix Outlook. If you use a Microsoft Exchange account, rebuilding the database will delete any information not synced with the server. Back up any Outlook data stored only on your computer before you rebuild the database.

Open the Send folder.

Delete all of the messages in the folder.

Quit Outlook.

Restart Outlook.

Try sending an email to see if the issue is resolved.

  • Quit all Microsoft Office applications.
  • Hold down the Option key and then click the Outlook icon in the Dock to open the Microsoft Database Utility.
  • Click the identity of the relevant database.
  • Click Rebuild.
  • Restart Outlook when the process is complete.

Fix Outlook Not Sending Emails in Outlook Online

Empty Your Inbox

If your inbox is full, you will not be able to send or receive any messages. Start by deleting any unwanted email messages from the inbox, then right-click Junk Mail and click Empty.

Quit all Microsoft Office applications.

Hold down the Option key and then click the Outlook icon in the Dock to open the Microsoft Database Utility.

Click the identity of the relevant database.

Click Rebuild.

Restart Outlook when the process is complete.

Try Again Tomorrow or Increase Your Sending Limit

Outlook.com limits the number of emails you can send in a day to deter spammers. If you have recently sent a large number of emails, save the draft and send it the following day.

Alternatively, increase your sending limit by updating security settings. Visit the Microsoft Account Security page, click Update Info, verify your identity, then follow the on-screen instructions to update your security settings.

Get the Latest Tech News Delivered Every Day