Accept Certificate Exception in macOS Mail

Provides a tutorial example on how to handle mail server certificate exceptions in macOS Mail.

If you are connecting macOS Mail to an internal local mail server, you will get server certificate exceptions, if self-signed root certificates are used on the server.

Here is what you should do in this case.

1. Click "Show Certificate" on the exception dialog box.

2. Review the certificate and make sure that it is the one used on your mail server.

3. Check the checkbox "Always trust ... when connecting to ..." and click "Continue".

4. Enter your macOS password to allow this certificate to be trusted and saved in "Keychain Access" on your macOS.

macOS Mail - Server Certificate Exception
macOS Mail - Server Certificate Exception

Note that the mail server may use 2 different self-signed certificates for POP3 and SMTP services separately.

If you want to see or remove those certificates, you can find them in "Launchpad > Other > Keychain Access", and under "login > Certificates".

Table of Contents

 About This Book

 Introduction to Linux Systems

 Cockpit - Web Portal for Administrator

 Process Management

 Files and Directories

 Users and Groups

 File Systems

 Installing CentOS

 SELinux - Security-Enhanced Linux

 Network Connection on CentOS

 Software Package Manager on CentOS - DNF and YUM

 Running Apache Web Server (httpd) on Linux Systems

 Running PHP Scripts on Linux Systems

 Running MySQL Database Server on Linux Systems

 Running Python Scripts on Linux Systems

 vsftpd - Very Secure FTP Daemon

 Postfix - Mail Transport Agent (MTA)

 Dovecot - IMAP and POP3 Server

Email Client Tools - Mail User Agents (MUA)

 "mailx" Command - Send and Read Emails

 "Alpine" - Terminal-Based Email Client

 SquirrelMail Webmail Installation on CentOS

 SquirrelMail Configuration on CentOS

 Thunderbird Installation on macOS

 Thunderbird Configuration for POP3S and SMTP

 Thunderbird to Accept POP3S Certificate Exception

 Thunderbird Configuratin for SMTPS Service

 macOS Mail Auto Configuration

 macOS Mail Manual Configuration

Accept Certificate Exception in macOS Mail

 Windows 10 Mail Configuration Failed

 SSL/TLS Connection Issue in Windows 10 Mail

 GCC - C/C++ Compiler

 Conda - Environment and Package Manager

 Tools and Utilities


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