IMAP4 (Internet Message Access Protocol version 4) is a protocol used by email clients to retrieve email messages from a mail server. It allows users to manage their email messages on the server without having to download them to their local devices permanently. IMAP4 supports functionalities such as folder management, message flagging, and synchronization of email across multiple devices, making it suitable for users who access their emails from different locations or devices.
The protocol number assigned to IMAP4 is 143. In networking, protocol numbers are used to identify specific protocols within the TCP/IP protocol suite. IMAP4 uses protocol number 143 to ensure that devices and servers can correctly identify and process IMAP4 traffic on the network.
IMAP (Internet Message Access Protocol) and IMAP4 are often used interchangeably to refer to the same protocol version. IMAP4 is simply the fourth version of the IMAP protocol, which has evolved over time to support enhanced features and functionality compared to its predecessors. Therefore, IMAP and IMAP4 both refer to the protocol used for retrieving and managing email messages on a remote server.
IMAP4 typically uses two ports for communication:
- Port 143: This is the default port for IMAP4 without SSL/TLS encryption.
- Port 993: This is the default port for IMAP4 with SSL/TLS encryption (IMAPS). SSL/TLS encryption adds a layer of security to IMAP4 communications, protecting email data from unauthorized access and interception during transmission.
An account type configured as IMAP4 in email settings indicates that the email client will use the IMAP4 protocol to retrieve and manage email messages from the configured email server. Users can choose IMAP4 when setting up their email accounts to enable features such as remote access, message synchronization across devices, and efficient management of email folders directly on the server.
