Christopher Kurtis Koeber:
> Hello,
>
> I am wondering if it is possible to greylist email systems based on:
>
> 1. An error code (450 Helo Command Rejected: Host not Found).
This is currently not supported. It would require a DNS-based
lookup table.
Instead, consider using a good DNSBL.
> 2. If they are a 'org' domain.
I hope that is just an example, and not a serious spam blocking
strategy.
/etc/postfix/main.cf:
smtpd_mumble_restrictions =
...
check_client_access hash:/etc/postfix/client_access
/etc/postfix/client_access:
unknown check_policy_service name-of-greylist-daemon-here
Many spambots don't have a usable client name (i.e. the FCRDNS
lookup fails) so Postfix uses a clientname of "unknown".
Wietse
