Three common mail protocols used for email communication are SMTP (Simple Mail Transfer Protocol), IMAP (Internet Message Access Protocol), and POP3 (Post Office Protocol version 3).
SMTP is responsible for sending outgoing email messages from a sender’s email client or server to the recipient’s email server. It operates on port 25 (or port 587 for secure communication using STARTTLS). SMTP ensures reliable delivery of emails across networks and supports features like email forwarding and relaying.
IMAP allows users to access and manage their email messages stored on a remote mail server from multiple devices. It supports functionalities such as folder management, message flagging, and synchronization of email across devices, ensuring consistency in email access and organization.
POP3 is another email retrieval protocol that allows users to download emails from a mail server to a local device. Unlike IMAP, which leaves copies of emails on the server by default, POP3 can be configured to delete emails from the server once they are downloaded. It operates on port 110 (or port 995 for POP3S, which uses SSL/TLS encryption).
HTTP (Hypertext Transfer Protocol) is a protocol used for retrieving hypertext pages on the World Wide Web. It is not specifically an email protocol. However, some email services and clients use HTTP-based protocols for accessing email services through web browsers, such as HTTP over Secure Sockets Layer (HTTPS) for secure webmail access.
The protocol commonly used for mailing, specifically for sending and receiving email messages over the internet, is SMTP (Simple Mail Transfer Protocol). SMTP handles the transmission of email messages between mail servers and is essential for delivering emails from senders to recipients worldwide. It works in conjunction with other protocols like POP3 and IMAP to facilitate end-to-end email communication and management.