Port 143 — IMAP
Quick reference for TCP/UDP port 143, used by IMAP. Includes what the service does, security guidance and related ports.
What is port 143?
Internet Message Access Protocol.
What port does IMAP use?
IMAP listens on port 143 by default.
Security guidance
High risk — do not expose to the internet
Port 143 (IMAP) is high-risk because the service it carries is a frequent target for credential attacks, brute force or unpatched-vulnerability scanning. Keep it bound to localhost or your VPN, never forward it directly on a router, and require strong authentication.
Related ports
Frequently asked
What is port 143 used for?+
Port 143 is the standard TCP/UDP port for IMAP. Internet Message Access Protocol.
What port does IMAP use?+
IMAP listens on port 143 by default.
Your IP Address Is Exposed Right Now
Every website you visit can see your real IP address and location. NordVPN encrypts your traffic and hides your identity with military-grade encryption. Stay anonymous online.