Which is the internet protocol
SMTP is the internet protocol.
SMTP (simple mail transfer protocol) is a TCP/IP protocol used in sending and receiving e-mail. However, since it is limited in its ability to queue messages at the receiving end, it is usually used with one of two other protocols, POP3 or IMAP that let the user save messages in a server mailbox and download them periodically from the server.
Internet protocol (IP):-
The internet protocol (IP) is the principal communications protocol in the internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the internet.