Set email content type to HTML

If you want to change your email template for WordPress you need to set your email content type to html/text. With the following filter hook you can change this e-mail content type.

// Set email content type
add_filter( 'wp_mail_content_type', 'set_content_type' );
function set_content_type( $content_type ){
   return 'text/html';
}