- Plesk for Linux
- Plesk for Windows
Cannot connect to Plesk mail server via POP3s:
PLESK_ERROR: SSL connection failed (certificate failed: certificate has expired (10))
Testing the POP3s connectivity via command line shows the following:
# openssl s_client -connect mail.example.com:995
verify error:num=10:certificate has expired
Connecting to the server via POP3 works fine.
Mail server SSL/TLS certificate is expired
Login to Plesk GUI and renew the certificate:
If Let's Encrypt certificate is used, follow the instructions from the article How to secure mail server with Let's Encrypt certificate?
If a purchased certificate is used, follow the instructions from the article How to secure a mail server with an SSL certificate?