Zimbra Tips : How To Enable PTR/Reverse DNS Lookup for Incoming Email

Posted by

Most of spam email sent from public IP who did not have PTR/Reverse DNS. What is PTR/Reverse DNS, you can find more information from Wikipedia 😀 : https://en.wikipedia.org/wiki/Reverse_DNS_lookup

If you have Zimbra and want to enable PTR/Reverse DNS lookup for incoming, you can perform the following command

su - zimbra
zmprov mcf +zimbraMtaRestriction "reject_unknown_client_hostname"

Please wait few minutes until Zimbra Postfix reload. Or you can also reloading Postfix manually 😉

Good luck and hopefully useful 🙂


  1. Hi Iman,

    i enabled DNS check but i want to receive email from server which does not configure reverse DNS. How can i do that ?


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.