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How to fix outlook is unable to connect to the proxy server error code 20

Alton Alexander
By Alton AlexanderUpdated on June 4th, 2022

Outlook is unable to connect to the proxy server error code 20 is a common error that can occur when Outlook is unable to connect to the Exchange server. This can happen for a number of reasons, including incorrect proxy settings, a firewall blocking the connection, or the Exchange server itself being down.

1. Restart your computer

  1. Locate the "Start" menu and click on "Control Panel"
  2. Click on "Network and Internet"
  3. Under the "Network and Sharing Center" section, click on "Restart"
  4. Under the "Restart Options" menu, select "Troubleshoot"
  5. Click on "Startup Settings"
  6. In the "Restart Options" menu, select " Enable Safe Mode with Networking "
  7. Click on "Restart"
  8. In the "Restart Options" menu, select "Disable Driver Signature Enforcement"
  9. Click on "Restart"
  10. In the "Startup Options" window, click on "Enable Safe Mode with Networking"
  11. In the "Network Connections" window, right-click on the "Local Area Connection" and select "Properties"
  12. Under the "Internet Protocol Version 4" heading, click on "Properties"
  13. Under the "Advanced" tab, click on "Use the following IP address"
  14. Enter the IP address of the proxy server in the "IP Address" box
  15. Click on "OK"
  16. In the "Startup Options" window, click on "Restart"
  17. In the "Network Connections" window, right-click on the "Local Area Connection" and select "Connect"
  18. Enter the user name and password of the proxy server in the "User Name" and "Password" boxes
  19. Click on "OK"
  20. In the "Startup Options" window, click on "Restart"

2. Make sure that the proxy server is entered correctly in the Outlook settings

  1. Open Outlook and click File .
  2. Click Options .
  3. Click the Advanced tab.
  4. Under the General section, click the Proxy server box.
  5. Enter the proxy server address and port in the appropriate fields.
  6. Click OK to close the Options dialog box.

3. Check your firewall settings

  1. In Windows Firewall, open the Advanced Security Settings window.
  2. In the left pane, under Connection Security Rules, click on the rule that you want to inspect.
  3. In the right pane, under Properties, look for the Connection Security section.
  4. On the General tab, make sure that the Enabled box is checkmarked.
  5. On the Proxy tab, make sure that the Proxy server is set to the appropriate address and port.
  6. If the firewall is blocking the connection, try unblocking the port using the Port Forwarding feature in Windows Firewall.
  7. If the firewall is not the problem, try restarting Outlook.