Port 587
submission · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | submission |
| Reference | RFC 6409 |
| Modified | 2011-11-17 |
Frequently asked questions
What is port 587 used for?
Port 587 is registered with the IANA for submission (TCP/UDP). Description: Message Submission.
Is port 587 a well-known port?
Yes. Port 587 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 587 is open?
Locally on Linux with ss -tulpn | grep ':587\b', on Windows with netstat -ano | findstr :587. To test a remote host use Test-NetConnection <host> -Port 587 in PowerShell or nc -zv <host> 587 on Linux/macOS.
How do I open port 587 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 587/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=587/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 587" -Direction Inbound -Protocol TCP -LocalPort 587 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | submission | Message Submission |
| UDP | submission | Message Submission |