We are seeing a lot of mail sitting in queues for bogus MX's that resolve to either RFC1918 space or to just bogus IP's in general. Before we implement, what exactly happens when a message in queue hits this list? Does an NDR get returned to the sender address or is the mail silently discarded? Since this is mostly to prevent some spam/virus backscatter in some cases, is it possible to silently discard?
Config parts in question:
BAD_MX_LIST = <; 0.0.0.0/8 ; 127.0.0.0/8 ; 10.0.0.0/8 ; 172.16.0.0/12 ; \
192.168.0.0/16 ; 224.0.0.0/3 ; 169.254.0.0/16; \
!2000::/3
smtp_routed:
driver = dnslookup
domains = !+local_domains
transport = remote_smtp
ignore_target_hosts = BAD_MX_LIST
--
Robert Blayzor
INOC, LLC
rblayzor@???
http://www.inoc.net/~rblayzor/
