Outlook TLS error: "None of the authentication methods supported by this client are supported by your server."

Symptoms

When using older email clients, such as Microsoft Outlook 2013 and earlier, on older operating systems, such as Windows 7, you encounter an error similar to the following:

CONFIG_TEXT: None of the authentication methods supported by this client are supported by your server.

Cause

In Version 68 of cPanel, we introduced new SSL ciphers to increase the security of the mail server; this enables TLS 1.2 and disables older SSL/TLS protocols, such as SSL 3 TLS 1.0. Older operating systems and email clients that do not utilize newer security protocols will be affected by this change.

Note: This is not a defect or an issue with cPanel, but an incompatibility with the outdated client software. Updating the client software to support TLS 1.2 will help maintain overall security.

Solution

To enable TLS 1.2 for Windows 7, you will need to patch your system to modify the registry. Be sure your system is fully updated through the update center, then download and install the patch from Microsoft's website.

Enable TLS 1.1 and 1.2 as the default secure protocols.

After the patch is installed, be sure to reboot your local computer to ensure the patch was applied. Once your system is back online, please try to connect to the cPanel server again.

Additional resources

Using system-wide cryptographic policies