ESMTP banner.
+`before_queue_filtering`: `<boolean>` ('default =' `0`)::
+
+Enable before queue filtering by pmg-smtp-filter
+
`conn_count_limit`: `<integer> (0 - N)` ('default =' `50`)::
How many simultaneous connections any client is allowed to make to this service. To disable this feature, specify a limit of 0.
Optional list of DNS white/blacklist domains (see postscreen_dnsbl_sites parameter).
+`dnsbl_threshold`: `<integer> (0 - N)` ('default =' `1`)::
+
+The inclusive lower bound for blocking a remote SMTP client, based on its combined DNSBL score (see postscreen_dnsbl_threshold parameter).
+
`dwarning`: `<integer> (0 - N)` ('default =' `4`)::
SMTP delay warning time (in hours).
The maximal number of message delivery requests that any client is allowed to make to this service per minute.To disable this feature, specify a limit of 0.
+`ndr_on_block`: `<boolean>` ('default =' `0`)::
+
+Send out NDR when mail gets blocked
+
`rejectunknown`: `<boolean>` ('default =' `0`)::
Reject unknown clients.