Fix Outlook Error 0x800CCC0E Cannot Connect To Server (2025)

Updated: 11/29/2025

You open Outlook, click Send and Receive, and instead of new messages you get an error dialog with 0x800CCC0E and text about not being able to connect to the email server. The account worked earlier, your password seems correct, and webmail still loads in a browser, which makes the error incredibly annoying. This code usually means Outlook cannot establish a proper connection to the mail server because of port, encryption, or firewall misconfiguration, and it will persist until those details are fixed.

Method 1: Verify Server Names, Ports, And Encryption

After making changes, use the Test Account Settings button in Outlook’s account configuration window. Watch whether both Log onto incoming mail server and Send test email message succeed, if either fails, recheck those specific values and correct any typos.

Method 2: Fix Authentication And Firewall Or Antivirus Conflicts

On Windows open Control Panel, then System and Security, Windows Defender Firewall, and click Allow an app or feature through Windows Defender Firewall. Ensure that Outlook has both Private and Public boxes checked, or add it manually if needed, then restart Outlook and run another send and receive.

Method 3: Repair The Outlook Profile And Network Stack

On Windows hit the Windows key, type cmd, right click Command Prompt, and select Run as administrator. Then run a sequence of network repair commands such as:

Restart your computer afterward and test Outlook again, especially if other apps have also shown occasional connection problems to external servers.