IMAP, or Internet Message Access Protocol, primarily uses TCP (Transmission Control Protocol) as its transport protocol. TCP ensures reliable and ordered delivery of data packets between the email client and the mail server, which is crucial for the synchronization and management of email messages.
IMAP operates exclusively over TCP/IP networks. TCP establishes a connection-oriented session between the client and the server, facilitating efficient and accurate transfer of email data. This connection-oriented approach ensures that data packets are delivered in sequence and reliably, maintaining the integrity of email operations such as message retrieval, folder management, and synchronization across multiple devices.
IMAP is a TCP-based protocol, not UDP (User Datagram Protocol). TCP’s connection-oriented nature is well-suited for IMAP’s requirements, which involve interactive sessions where clients can manage and manipulate email messages stored on the server.
The secure transport port for IMAP over TLS/SSL (IMAPS) is TCP port number 993. IMAPS encrypts the communication between the email client and the server using SSL/TLS protocols, enhancing security by preventing eavesdropping and protecting sensitive information such as email content and login credentials. When configuring an email client to use IMAPS, users typically specify the server address (e.g., imap.example.com) and port number 993 for secure communication.