I'm having a strange issue with wp_mail() -- for some admin users, the sent message includes a
Content-Transfer-Encoding: quoted-printable
header, which breaks the HTML of the email message.
I'm using:
add_filter('wp_mail_content_type', create_function('', 'return "text/html";'));
add_filter('wp_mail_charset', create_function('', 'return "UTF-8";'));
To define the content type and charset.
This header doesn't get added for other users and the same email script sends normally.
Has anyone else encountered this? What's going on? Thanks!