What is SMTP and MAP?

Published on February 20, 2025

SMTP (Simple Mail Transfer Protocol)

SMTP is a protocol used for sending emails. It works as a push protocol, meaning it pushes (sends) emails from the sender's email client to the recipient's email server. SMTP is responsible for outgoing mail only.

How SMTP Works:

  1. When you send an email, your email client (like Gmail, Outlook, or Thunderbird) connects to an SMTP server.
  2. The SMTP server processes the email and determines the recipient's email server.
  3. The email is then forwarded to the recipient's mail server, where it waits for the recipient to retrieve it.

Common SMTP Ports:

  • Port 25 – Default SMTP port (often blocked by ISPs to prevent spam).
  • Port 587 – Secure SMTP (TLS encryption).
  • Port 465 – Legacy secure SMTP (SSL encryption).

MAP (Likely Referring to IMAP - Internet Message Access Protocol)

IMAP is a protocol used for receiving emails. Unlike SMTP, which is for sending, IMAP allows you to access emails stored on a mail server without downloading them permanently to your device.

How IMAP Works:

  1. When you check your email, your email client connects to the IMAP server.
  2. The IMAP server keeps the emails stored on the server, allowing you to read, delete, or organize them without downloading them.
  3. Any changes made (reading, deleting, moving emails) sync across all devices.

Common IMAP Ports:

  • Port 143 – Default IMAP (non-secure).
  • Port 993 – Secure IMAP (SSL/TLS encryption).

Difference Between SMTP and IMAP

Feature SMTP IMAP
Purpose Sending emails Receiving emails
Storage No storage (just forwards emails) Emails stay on the server
Access Works with a sender's email client Works with multiple devices synchronizing emails
Encryption Ports 465, 587 993