View SSL certficate Details

To view certificate details

openssl x509 -text -noout -in SSL_FILE.crt

For web server

openssl s_client -showcerts -connect serverok.in:443

curl -vI https://serverok.in

IMAP via SSL

openssl s_client -showcerts -connect mail.yourdomain.com:993 -servername mail.yourdomain.com

POP3 via SSL

openssl s_client -showcerts -connect mail.example.com:995  -servername mail.yourdomain.com

SMTP via SSL

openssl s_client -showcerts -connect mail.yourdomain.com:465  -servername mail.yourdomain.com

SMTP via TLS/StartTLS

openssl s_client -starttls smtp -showcerts -connect mail.yourdomain.com:25  -servername mail.yourdomain.com

See SSL