PHP Mail Script with SMTP Authentication

<?php
// Basic usage
$to = "to@fast2host.com";
$nameto = "Recipient Name";
$from = "from@fast2host.com";
$namefrom = "Sender Name";
$subject = "Hello World Again!";
$message = "World, Hello!";

authSendEmail($from, $namefrom, $to, $nameto, $subject, $message);

// Function to send email with SMTP authentication
function authSendEmail($from, $namefrom, $to, $nameto, $subject, $message) {
    // SMTP + Server Details
    $smtpServer = "mail.YOUR-DOMAIN.com";
    $port = 25;
    $timeout = 30;
    $username = "your-email@domain.com";
    $password = "your-email-password";
    $localhost = "mail.YOUR-DOMAIN.com";
    $newLine = "\r\n";

    // Connect to SMTP server
    $smtpConnect = fsockopen($smtpServer, $port, $errno, $errstr, $timeout);
    $smtpResponse = fgets($smtpConnect, 515);

    if(empty($smtpConnect)) {
        return "Failed to connect: $smtpResponse";
    }

    // Authenticate
    fputs($smtpConnect,"AUTH LOGIN" . $newLine);
    fgets($smtpConnect, 515);
    fputs($smtpConnect, base64_encode($username) . $newLine);
    fgets($smtpConnect, 515);
    fputs($smtpConnect, base64_encode($password) . $newLine);
    fgets($smtpConnect, 515);

    // Say Hello
    fputs($smtpConnect, "HELO $localhost" . $newLine);
    fgets($smtpConnect, 515);

    // Mail From / RCPT To
    fputs($smtpConnect, "MAIL FROM: $from" . $newLine);
    fgets($smtpConnect, 515);
    fputs($smtpConnect, "RCPT TO: $to" . $newLine);
    fgets($smtpConnect, 515);

    // Send Data
    fputs($smtpConnect, "DATA" . $newLine);
    fgets($smtpConnect, 515);

    $headers = "MIME-Version: 1.0" . $newLine;
    $headers .= "Content-type: text/html; charset=iso-8859-1" . $newLine;
    $headers .= "To: $nameto <$to>" . $newLine;
    $headers .= "From: $namefrom <$from>" . $newLine;

    fputs($smtpConnect, "To: $to\nFrom: $from\nSubject: $subject\n$headers\n\n$message\n.\n");
    fgets($smtpConnect, 515);

    // Quit
    fputs($smtpConnect,"QUIT" . $newLine);
    fgets($smtpConnect, 515);
}
?>
    

• $smtpServer: Replace with your mail server (e.g., mail.yourdomain.com).
• $username / $password: Use your full email address and password.
• $port: Default is 25. Use 587 or 465 if SSL/TLS is required.
• $localhost: Typically your domain name or mail server hostname.

• Use authenticated SMTP for reliable delivery.
• Consider using PHPMailer or SwiftMailer for modern, secure email handling.
• Always test your script with a valid recipient before deploying live.
• Check if your hosting requires SSL/TLS and adjust port settings accordingly.