From: ciberciti  (15 Greatest Open Source Terminal Applications Of 2012) for personal reference:

Connect to mail server for testing purpose

openssl s_client -connect smtp.server.com:995
openssl s_client -connect smtp.server.com:995 -CApath /etc/ssl

Encrypt file (using openssl)

openssl aes-256-cbc -salt -in records-fy-2011-12.dbx -out records-fy-2011-12.dbx.aes

Decrypt file (using openssl)

openssl aes-256-cbc -d -in records-fy-2011-12.dbx.aes -out records-fy-2011-12.dbx

Cheers,

Pedro Oliveira