Port 109: POP2
Port 109 is POP2, an early version of the Post Office Protocol for downloading mail. It was superseded by POP3 on port 110 decades ago and is essentially unused today.
TCPEmailUnencrypted by defaultIANA assigned
| Port number | 109 |
|---|---|
| Service | Post Office Protocol v2 |
| Protocol | TCP |
| Category | |
| Default encryption | No |
Security note. Port 109 is not encrypted by default. Restrict it to trusted networks, or use an encrypted alternative where one exists, to avoid exposing credentials and data in transit.
Frequently asked questions
What is port 109 used for?
Port 109 is POP2, an early version of the Post Office Protocol for downloading mail. It was superseded by POP3 on port 110 decades ago and is essentially unused today.
Is port 109 TCP or UDP?
Port 109 (POP2) uses TCP.
Is port 109 secure?
Port 109 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 109 on my firewall?
Only if you specifically need POP2. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.