Protocol with SSL/TLS to encrypt the transmission transfer-send mail across TCP/IP networks use SMTPS and SMTP (Simple Mail Transfer Protocol). Differs from the usual SMTP port number (typically 465 number) method to start communications with SSL/TLS from the outset, using a method supports the procedure called the “”STARTTLS””, begin to communicate with SMTP usually supports both SSL/TLS or SSL/TLS reconnect two and the latter has been established in the current.