Crypt::OpenSSL::SMIME is a brain dead minimalistic not yet secure for use by paranoid people wrapper around OpenSSL library which was extremely useful for us at YASP Software Ltd to send sensitive information to Outlook and Mozilla mailboxes and requires NO additional support from the mail reader software to decrypt messages unlike PGP. version 0.04 should compile with OpenSSL 1.x Look at t/README for openssl help