Content-Type header not being set

I believe there is a bug in wp-mail-api.php line 381. The Content-Type header will never be set because it’s removed from the $headers array earlier on and the isset($headers['Content-Type']) check will always return false.

// Set the content-type and charset
$charset = apply_filters('wp_mail_charset', $charset);
if (isset($headers['Content-Type'])) {
    if (!strstr($headers['Content-Type'], 'charset')) {
        $headers['Content-Type'] = rtrim($headers['Content-Type'], '; ') . "; charset={$charset}";
    }
}

I’m trying to set the content type to text/html; charset=UTF-8 but the email is being delivered with text/html; charset=ascii – I presume Mailgun server is automatically adding the header but with the wrong charset.

• This topic was modified 2 years ago by brettwhiteman.