What is the IMAP protocol and which port does its secure variant use?

IMAP (Internet Mail Access Protocol) is an interactive mail access protocol used to retrieve emails from a mail server. Its secure variant, IMAP4_SSL, uses SSL encryption and operates on port 993. For penetration testing, using [IMAP4_SSL](/news/penetration-basics-reading-emails-using-the-imap-protocol) ensures that email data is transmitted securely, preventing leakage during mailbox analysis.