SMTP-(simple mail transfer protocol)-
1. It is used for sending email i.e. It is designed to send and distribute outgoing E-mail.
2. It is a set commands that authenticates and directs the transfer of email.
3. SMTP- we can say smtp is “sending mail to people”. It is similar to a mailman.
4.It uses TCP protocol. (TCP guarantees email delivery(assuming that the email address exists).