How to send attachments with PHP Mail()?

PHPMailer is the easier option by a very large margin compared to trying to do it yourself with PHP's built-in mail() function. PHP's mail() function really isn't very good.

To use PHPMailer:

• Download the PHPMailer script from here: http://github.com/PHPMailer/PHPMailer
• Extract the archive and copy the script's folder to a convenient place in your project.
• Include the main script file -- require_once('path/to/file/class.phpmailer.php');

Now, sending emails with attachments goes from being insanely difficult to incredibly easy:

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

$email = new PHPMailer();
$email->SetFrom('you@example.com', 'Your Name'); //Name is optional
$email->Subject   = 'Message Subject';
$email->Body      = $bodytext;
$email->AddAddress( 'destinationaddress@example.com' );

$file_to_attach = 'PATH_OF_YOUR_FILE_HERE';

$email->AddAttachment( $file_to_attach , 'NameOfFile.pdf' );

return $email->Send();

It's just that one line $email->AddAttachment(); -- you couldn't ask for any easier.

If you do it with PHP's mail() function, you'll be writing stacks of code, and you'll probably have lots of really difficult to find bugs.