try new mailboxcheck

zimbraAddressAvailable.php

@@ -14,7 +14,7 @@ use WHMCS\Database\Capsule;
 $whmcs = App::self();
 $productID = $_GET['pid'];
 $accessData = array('zimbraServer' => '', 'adminUser' => '', 'adminPass' => '');
-$serverGroupIDObj = Capsule::table('tblhosting')
+$serverGroupIDObj = Capsule::table('tblproducts')
 	->select('servergroup')
 	->where('id', '=', $productID)
 	->get();