What is the default port number for IMAP?
Answer
143
The default port number for IMAP is 143.
IMAP, or Internet Message Access Protocol, lets an email client access and manage messages stored on a remote mail server. A client can read, organize, flag, and delete mail while keeping the mailbox synchronized across multiple devices.
Standard IMAP connections use TCP port 143. Because ordinary IMAP traffic may begin unencrypted, servers can use STARTTLS to upgrade the connection to encryption. A separate secure variant, IMAPS, typically uses TCP port 993 for IMAP over SSL/TLS.
Port confusion is common because other email protocols use familiar numbers. SMTP traditionally uses port 25 for server-to-server delivery, SMTP submission commonly uses 587, and POP3 commonly uses 110. IMAP is a retrieval and mailbox-management protocol, whereas SMTP is responsible for sending messages.