Simple Mail Transfer Protocol. Sends emails between servers. Often blocked by ISPs on residential connections.
Test it now with our Port Scanner
| Port | 25 |
|---|---|
| Service | SMTP |
| Protocol | TCP |
| Encrypted | No |
| Common Use | Simple Mail Transfer Protocol |
Online: Use our Port Scanner — enter your IP and port 25.
Command line:
nc -zv your-server-ip 25 (Mac/Linux)
Test-NetConnection -ComputerName your-server-ip -Port 25 (PowerShell)
Check locally:
ss -tlnp | grep :25 (Linux) netstat -an | findstr :25 (Windows)