as I wrote earlier Google mail servers got blacklisted , but it was only the beginning. Now I got complains from the client that hotmail.com users also get mail bounced because of this list . So, as running after each and every IP blocked by this list endlessly wasn't the best use of my time, I disabled this specific RBL in eSafe. So far no complains neither about bounced mail nor increased spam. The screenshot below shows where to find this RBL in the eSafe.