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