How to check port number for mail

To check the port number used for mail, you can follow these steps:

Method 1: Using the netstat command (Windows, macOS, Linux)

  1. Open a command prompt or terminal window.
  2. Type the following command and press Enter:
    netstat -an | findstr "25" | findstr "587"

    This command will show you the listening ports for SMTP (25) and Submission (587) services.

Method 2: Using the telnet command (Windows, macOS, Linux)

  1. Open a command prompt or terminal window.
  2. Type the following command and press Enter:
    telnet yourdomain.com 25

    Replace yourdomain.com with your actual domain name or IP address.

If the connection is successful, you should see a response like:

Trying 192.0.2.1...
Connected to yourdomain.com.
Escape character is '^]'.
220 yourdomain.com ESMTP

This indicates that the SMTP server is listening on port 25.

If you get a connection refused error, it may indicate that the port is blocked or the server is not listening on that port.

Method 3: Using a network scanning tool (Windows, macOS, Linux)

  1. Download and install a network scanning tool like Nmap or OpenVAS.
  2. Run the tool and select the "Port Scan" option.
  3. Enter the IP address or domain name of your mail server.
  4. Set the port range to 1-1024 (or a specific range if you know the port number).
  5. Run the scan and look for the port numbers in the output.

Method 4: Checking your mail client settings (Windows, macOS)

  1. Open your email client (e.g., Microsoft Outlook, Mozilla Thunderbird).
  2. Go to the "Settings" or "Preferences" menu.
  3. Look for the "Account Settings" or "Mail Server" section.
  4. Check the "Port" or "SMTP Port" setting. It should be set to 25 (SMTP) or 587 (Submission).

Remember to replace yourdomain.com with your actual domain name or IP address in the examples above.