Simple SMTP Relay Server.

A simple SMTP relay server in rust. The default host is local host and the default port is 2525.

This server listens for the SMTP emails and relays them.

Procedure

• Start the server. This will make the server listen on the port specified in the config.

  > smtprelay-rs -c <CONFIG_PATH>

• Send mail to the server. You could use any tool to send the mail to the listening port.

Example 1

A sample python snippet.

    #!/usr/bin/env python
    import socket
    
    TCP_IP = 'localhost'
    TCP_PORT = 2525
    BUFFER_SIZE = 1024
    MESSAGE = """
    HELO yourdomain.com
    MAIL FROM: test@yourdomain.com
    RCPT TO: user@example.com
    DATA
    It works!
    .
    QUIT
    EOT"""
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect((TCP_IP, TCP_PORT))
    s.send(MESSAGE)
    data = s.recv(BUFFER_SIZE)
    s.close()

Example 2

• Use netcat to send mail to the server. Use the host and port used in the listener section of the config.

  > nc localhost 2525 <<EOT

• Construct a basic test email.

  > HELO yourdomain.com
  > MAIL FROM: test@yourdomain.com
  > RCPT TO: user@example.com
  > DATA
  > It works!
  > .
  > QUIT
  > EOT
  

Note

Some SMTP servers block open relay servers due to spamming. On some inboxes the mail may appear in the spam category.