Are there any specific guidelines or recommendations for structuring the header of an email when using the mail() function in PHP?

When using the mail() function in PHP to send emails, it is important to structure the headers correctly to ensure proper delivery and formatting of the email. Some key guidelines for structuring the header include specifying the From, Reply-To, and Content-Type headers, as well as any additional headers such as CC or BCC if needed. It is also recommended to encode any special characters in the headers using the mb_encode_mimeheader() function. 

$to = "recipient@example.com";
$subject = "Example Subject";
$message = "This is a test email.";

$headers = "From: sender@example.com\r\n";
$headers .= "Reply-To: replyto@example.com\r\n";
$headers .= "CC: cc@example.com\r\n";
$headers .= "BCC: bcc@example.com\r\n";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: text/html; charset=UTF-8\r\n";

// Encode any special characters in the headers
$subject = mb_encode_mimeheader($subject, "UTF-8", "Q", "\r\n", 10);

// Send the email
mail($to, $subject, $message, $headers);

Related Questions