Port 220
imap3 · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | imap3 |
Frequently asked questions
What is port 220 used for?
Port 220 is registered with the IANA for imap3 (TCP/UDP). Description: Interactive Mail Access Protocol v3.
Is port 220 a well-known port?
Yes. Port 220 is in the range 0–1023 (system or well-known ports). On Linux and macOS only privileged processes may bind to these ports.
How do I check whether port 220 is open?
Locally on Linux with ss -tulpn | grep ':220\b', on Windows with netstat -ano | findstr :220. To test a remote host use Test-NetConnection <host> -Port 220 in PowerShell or nc -zv <host> 220 on Linux/macOS.
How do I open port 220 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 220/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=220/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 220" -Direction Inbound -Protocol TCP -LocalPort 220 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | imap3 | Interactive Mail Access Protocol v3 |
| UDP | imap3 | Interactive Mail Access Protocol v3 |