How to Configure TLS Client Certificate Authentication for IMAP & SMTP in macOS Mail app — Step‑by‑Step Video Guide

The Mail app on macOS ships with more features than any other OS, including support for S/MIME and the TLS client certificate authentication method for both IMAP and SMTP. As far as I know, it isn't fully supported by any client other than the open-source Claws Mail client for GNU/Linux and Windows.

Configuring TLS client certificate authentication for IMAP/SMTP is relatively straightforward in the Mail app on macOS. That being said, there are a few things that could frustrate new users, and no macOS user should have to deal with that. I hope Apple's development team takes this feedback on board.

Watch this step-by-step video guide to learn how to set up a TLS Client Certificate for accessing your IMAP/SMTP server via the Mail app on macOS

• Obtain your client certificate/key pair from your email provider.
• Import it into Keychain Access.
• Open the Mail app to configure your account.
• Configure the settings in the Mail app to fix the server settings for IMAP/SMTP.
• Send and receive test emails, and you're all set!

Please let me know in the comments section if you would like to see more videos like this.