Internet Message Access Protocol

The Internet Message Access Protocol, or IMAP, is a protocol that has been standardised as part of the Internet and is used by email clients in order to access email messages from a mail server through a connection based on TCP/IP. RFC 9051 is the document that defines IMAP.

IMAP was developed with the intention of enabling comprehensive administration of an email box by numerous email clients. As a result, clients often keep messages on the server until the user actively deletes them from their account. 143 is the default port number that an IMAP server uses to listen on. IMAP over SSL/TLS, abbreviated as IMAPS, has the port number 993 allocated to it.

IMAP, which together with the older POP3 (Post Office Protocol), is one of the two most widespread standard protocols for the retrieval of email, is supported by almost all email clients and servers that are now in use. Support for IMAP and POP3 is offered by a large number of webmail service providers, including Google and Outlook.com, amongst others.

Internet Message Access Protocol is an application layer Internet protocol that enables an e-mail client to access email stored on a distant mail server. This functionality is provided by the Internet Message Access Protocol. RFC 9051 is the document that defines the current version. The standard listening port for an IMAP server is 143, however the port number for IMAP over SSL/TLS (IMAPS) is 993.

Messages that are received through email are sent to a server that manages email and saves them in the inbox of the receiver. The user obtains the messages by using an email client that adheres to any one of a number of different protocols for the purpose of email retrieval. To retrieve email, almost all clients and servers support POP and IMAP, despite the fact that some clients and servers preferentially use vendor-specific, proprietary protocols. This gives users the ability to use any e-mail client they want, such as Pegasus Mail or Mozilla Thunderbird, to access the servers in question, and also enables the clients to be used with other servers.

Messages sent from email clients that utilise IMAP will often remain on the server until the user takes active steps to erase them. It is possible for numerous clients to control the same mailbox thanks to this and other aspects of the IMAP operation. The majority of email clients fetch messages using both Post Office Protocol (POP) and Internet Message Access Protocol (IMAP). IMAP provides access to the storage area for e-mail. Clients have the option of storing local copies of the messages; however, these copies are only regarded to be a temporary cache.