What are some common pitfalls for beginners when trying to create a form mailer in PHP?

One common pitfall for beginners when creating a form mailer in PHP is not properly sanitizing user input, which can lead to security vulnerabilities such as SQL injection or cross-site scripting attacks. To solve this, always use functions like htmlspecialchars() or mysqli_real_escape_string() to sanitize user input before using it in your mailer script.

// Sanitize user input before using it in the mailer script
$name = htmlspecialchars($_POST['name']);
$email = htmlspecialchars($_POST['email']);
$message = htmlspecialchars($_POST['message']);