Hi,
I have the same problem in WP version 3.8 and now in 3.9.
You can do this changes in wpmandrill.php
from line 54
if( function_exists('wp_mail') ) {
$r = new ReflectionFunction('wp_mail');
$original = ($r->getFileName() === ABSPATH . WPINC . '/pluggable.php');
if (!$original) {
self::$conflict = true;
add_action('admin_notices', array(__CLASS__, 'adminNotices'));
return;
}
}
also replace :
if( self::isConfigured() ) {
with
if( self::isConfigured() && !function_exists('wp_mail') ) {
The plugin will work perfectly after that.