Email::sender::transport::smtps is an email::sender transport used to send email over smtp, either with or without secure sockets (ssl/tls). it uses net::smtps.

email::sender is a perl module providing an interface to send email via many backends, including sendmail, smtp, delivering directly to mbox file, etc.

net::smtps is a wrapper around net::smtp which adds support for ssl/starttls.