Hi, I have reject_unknown_client in my smtpd_recipient_restrictions and have 2 questions regarding the working of this option. I looked up the documentation, but would love to cross check my understanding with other users.
1. I have noticed that the following scenario results in rejection with error - 450 4.7.1 Client host rejected: cannot find your hostname 1. A host connects to my postfix server from IPAddressA 2. IPAddressA has a proper PTR record pointing to HostnameA 3. HostnameA has an A record and points to IPAddressB 4. IPAddressB does not have a PTR record. The above behavior suggests that postfix expects a PTR -> A -> PTR -> A mapping. Is my understanding right? Or is PTR -> A -> PTR adequate? 2. If IPAddressA points to HostnameA and HostNameA points to IPAddressB ( not to IPAddressA), should that be considered as an unknown_client and eligible for rejection? Thanks Krishnan
