How can developers ensure that emails sent from PHP scripts comply with RFC standards for proper display and delivery?

To ensure that emails sent from PHP scripts comply with RFC standards for proper display and delivery, developers should use the PHP `mail()` function along with proper headers and encoding. This includes setting the Content-Type header to text/plain or text/html, using base64 encoding for non-ASCII characters, and ensuring that line breaks are correctly formatted with \r\n.

$to = "recipient@example.com";
$subject = "Test Email";
$message = "This is a test email.";
$headers = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=UTF-8" . "\r\n";
$headers .= "From: sender@example.com" . "\r\n";

mail($to, $subject, $message, $headers);