Linux Tutorials - Herong's Tutorial Examples - v5.42, by Herong Yang
Thunderbird to Accept POP3S Certificate Exception
This section provides a tutorial example on how to handle POP3S server Certificate Exception on Thunderbird. Just click 'Confirm Security Exception' to accept and store the default certificate provided by Dovecot server.
If you are running a POP3S (POP3 with SSL/TLS) service with Dovecot. Dovecot will be using a dummy self-signed root certificate by default.
When you connect Thunderbird to this POP3S service for the first time, you will get certificate exception. Don't worry. Here is how you can handle this exception.
1. Click "Confirm Security Exception". This tells Thunderbird to accept and store this certificate.
2. Click "Get Messages" to continue retrieving emails from the POP3S server.
If you are curious about this dummy self-signed root certificate, click "Thunderbird > Preferences > Privacy & Security" menu. Then click "Manage Certificates" to open it. The dummy certificate shows the following:
Subject Name Organizational Unit: IMAP server Common Name: imap.example.com Email Address: email@example.com ...
The subject name, IMAP server, suggests that Dovecot is sharing the same dummy certificate for both IMAPS and POP3S service.
If you don't like this default certificate, Read Dovecot to replace it with your own certificate.
Table of Contents
Cockpit - Web Portal for Administrator
SELinux - Security-Enhanced Linux
Software Package Manager on CentOS - DNF and YUM
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
Thunderbird Installation on macOS
Thunderbird Configuration for POP3S and SMTP
►Thunderbird to Accept POP3S Certificate Exception
Thunderbird Configuration for IMAPS and SMTP
Thunderbird Configuratin for SMTPS Service
macOS Mail Manual Configuration
Accept Certificate Exception in macOS Mail
Windows 10 Mail Configuration Failed
SSL/TLS Connection Issue in Windows 10 Mail
LDAP (Lightweight Directory Access Protocol)