Before configure this guidance, please make sure you’ve configured SPF checking from this link : https://imanudin.net/2016/03/11/zimbra-tips-how-to-enable-spf-checking-for-incoming-connection/. When you’ve done, by default will reject SPF only if configured fail (-). If SPF none or SPF soft fail, email will pass and given some score. If you want to block sender did not have SPF or soft fail, ..
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 ..
From previous article, you can configure and validate DKIM records on Zimbra which is used to increase email reputation. The configuration will increase reputation for outgoing email. But, how to enable DKIM/DomainKeys checking for incoming connection? By enable DKIM/DomainKeys checking, you can reject every incoming email who did not have DKIM/DomainKeys. By default, Zimbra only configure OpenDKIM as ..
Usually, i am configure spf to my server for outgoing purpose. The spf records are defined in public dns use txt records. But, how to enable spf checking if there connection to my server? The following is step by step how to enable spf checking for incoming connection. You need to enable cbpolicyd as in the following ..