Check SSL certificate expiration on remote SMTP server
Check SSL certificate expiration on a remote SMTP server using openssl
printf 'quit\n' | openssl s_client -servername <servername> -connect <ip/hostname>:<port> | openssl x509 -enddate -noout
Check SSL certificate expiration on a remote SMTP server using openssl
printf 'quit\n' | openssl s_client -servername <servername> -connect <ip/hostname>:<port> | openssl x509 -enddate -noout