Here are some simple commands you can use to test a SSL/TLS enabled site or service.

Simple Connect

openssl s_client -connect dr.dk:443

Test with CA Validation

openssl s_client -connect localhost:9000 -CApath /etc/grid-security/certificates

Test a SMTP server

openssl s_client -connect mail.example.com:25 -starttls smtp

Test with Displayed Certificates

openssl s_client -showcerts -connect  www.thawte.com:443