IMAP stands for Internet Message Access Protocol. IMAP is a standard protocol for accessing e-mail on a remote server from a local client. IMAP is an application layer Internet Protocol that uses underlying transport layer protocols to create host-to-host communication services for applications. This allows the use of the remote mail server.

The IMAP architecture allows users to send and receive emails over a remote server without support from a particular device. This type of email access is ideal for devices that receive or respond to email from home desktop or office computers.

When a user requests an email, it is routed through a central server. This maintains a storage document for the email files. Some of the benefits of IMAP are deleting messages, searching for keywords in the body of emails, creating and managing multiple mailboxes or folders, and displaying headers for easy visual browsing of emails.

IMAP is still widely used, but gMail, Hotmail, Yahoo Mail etc. It is less important now as a lot of e-mails are sent via web-based interfaces.