Outlook error 0x800CCC0B is a super annoying error that can appear on Windows 11 and almost always stops Outlook from sending emails properly. It usually occurs when Outlook fails to connect to the outgoing mail server (SMTP) or when there are incorrect authentication or port settings. While it sounds complicated, there are a few simple things you can do to solve this issue.

Takeaways:

  1. Learn how to fix Outlook error 0x800CCC0B on Windows 11
  2. Find out why Outlook keeps showing error 0x800CCC0B
  3. Fix SMTP connection and configuration problems

How to Fix Outlook Error 0x800CCC0B on Windows 11

Rather than jumping into complicated fixes straight away, start with this solution as it tends to solve the problem for most people, most of the time. It's also super quick and easy.

  • Open Control Panel.
  • Go to Programs > Programs and Features.
  • Select Microsoft Office and click Change.
  • Choose Online Repair and follow the prompts to complete the repair.

This should solve the issue in many cases. If it doesn't, the problem may be related to network connectivity or incorrect mail server settings.

Update Windows

Outdated Windows system files can sometimes cause compatibility problems with Outlook.

  • Type Updates in the Windows search bar and press Enter.
  • If updates are available, click Install updates.
  • If not, click Check for updates.
  • Install any optional updates as well.
  • Once the process is complete, restart your computer. It usually restarts automatically.

How_to_Fix_Outlook_Error_0x800CCC0B_on_Windows_11 copy

Verify SMTP Settings

Incorrect SMTP settings are one of the most common causes of error 0x800CCC0B.

  • Open Outlook and go to File > Account Settings.
  • Select your email account and click Change.
  • Confirm that the Outgoing mail server (SMTP) matches the settings provided by your email service provider.
  • Verify the SMTP port number and encryption type.

A lot of providers use settings such as:

  • Port 587 with TLS
  • Port 465 with SSL

  • Save the changes and restart Outlook.

Repair Outlook Data Files

Corrupted PST or OST files can interfere with sending and receiving emails.

  • Close Outlook.
  • Open the search bar and type Control Panel, then open it.
  • Set View by to Small icons.
  • Select Mail and click Data Files.
  • In Account Settings, note the location of your PST file.

Now open File Explorer and navigate to:

C:\Program Files\Microsoft Office\Office[version]\

or

C:\Program Files\Microsoft Office\root\Office16

Launch scanpst.exe (Inbox Repair Tool).

  • Click Browse and select your PST or OST file.
  • Click Start.
  • Follow the prompts to repair the file.

Update Outlook

Running an outdated version of Outlook can sometimes trigger errors like 0x800CCC0B.

  • Open Outlook.
  • Click File.
  • Select Office Account (or Account depending on your version).
  • Under Product Information, click Update Options.
  • Select Update Now.
  • After updating, restart Outlook.

Repair or Reset Outlook From Settings

  • Open Settings.
  • Go to Apps > Installed Apps > Outlook.
  • Scroll down and click Repair and wait for the process to complete. If this doesn't work, go back and select Reset. Keep in mind resetting will require you to sign back into everything and set your settings again.