gistfile1.txt

#!/bin/bash

# === Configuration ===
SMTP_SERVER="smtp.example.com"
SMTP_PORT="25"  # Use 25 for no encryption. Use 587/465 only with TLS support (see note below)
EHLO_DOMAIN="myhost.example.com"
MAIL_FROM="[email protected]"
RCPT_TO="[email protected]"
SUBJECT="Netcat Test Email"
BODY="Hello,\r\n\r\nThis is a test email sent using netcat from a Bash script.\r\n\r\nRegards,\r\nNetcat Tester"

# === SMTP Conversation ===
{
  printf "EHLO $EHLO_DOMAIN\r\n"
  sleep 1
  printf "MAIL FROM:<$MAIL_FROM>\r\n"
  sleep 1
  printf "RCPT TO:<$RCPT_TO>\r\n"
  sleep 1
  printf "DATA\r\n"
  sleep 1
  printf "Subject: $SUBJECT\r\n"
  printf "To: <$RCPT_TO>\r\n"
  printf "From: <$MAIL_FROM>\r\n"
  printf "\r\n"
  printf "$BODY\r\n"
  printf ".\r\n"
  sleep 1
  printf "QUIT\r\n"
} | nc "$SMTP_SERVER" "$SMTP_PORT"