Cleo’s SMTP and SMTPs File Transfer Protocols
SMTP/SMTPs (Simple Mail Transfer Protocol/Secure or SMTP over SSL): This a protocol for sending email messages between servers. Most email systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an email client. SMTPs is a method for securing SMTP with transport layer security and is intended to provide authentication of the communication partners. SMTPs is not an extension of SMTP; it is a way to secure SMTP at the transport layer.