Final answer:
SMTP, the Simple Mail Transfer Protocol, uses TCP, the Transmission Control Protocol, to ensure reliable delivery of email messages over the Internet.
Step-by-step explanation:
Simple Mail Transfer Protocol (SMTP) uses Transmission Control Protocol (TCP) as its transport service to communicate. SMTP is a protocol used for sending emails across the Internet. Unlike UDP, which is also a transport protocol, TCP guarantees the delivery of data packets in the correct order without loss, which is essential for sending reliable email messages.
IMAP is not a transport protocol, but rather a mail retrieval protocol used by email clients, and FTP is the File Transfer Protocol used for transferring files rather than sending emails.
The Simple Mail Transfer Protocol (SMTP) uses TCP (Transmission Control Protocol) to communicate. TCP is a reliable and connection-oriented transport service that guarantees the delivery of data packets in the correct order.
SMTP utilizes TCP's reliability to ensure that email messages are sent and received accurately. TCP establishes a connection between the sender and recipient, breaks the data into packets, and manages error detection and retransmission if needed.