Rodre Ghorashi-Zadeh wrote:
Hello List,
This is my first post to this list so please excuse any indiscretions. I have a
problem where my carrier's/ISP entire CIDR/Subnet is blacklisted by some email
carriers. My ISP does provide a relay/smarthost for outbound SMTP but it doesn't use
TLS, so I don't want to route all of our company's email through it by setting the
'relayhost' parameter. I have been able to put the destination domains in the
/etc/postfix/transport file and use my ISPs smarthost as the next hop MTA, however,
I noticed that most of the destination domains I am experiencing problems with are
all being handled by a specific email carrier. What I want to do is put that email
carriers entire CIDR into my postfix configuration and basically say "if the MX
host for any destination domains IP address belongs to this CIDR, use my ISPs
smarthost, instead of having to add the domains one at a time. Is this possible?
~Rodre
You can use a check_recipient_mx_access map with a FILTER
action to set the next-hop destination to your IPS' smarthost.
http://www.postfix.org/postconf.5.html#check_recipient_mx_access
http://www.postfix.org/access.5.html
# main.cf
smtpd_sender_restrictions =
check_recipient_mx_access cidr:/etc/postfix/smarthost.cidr
# smarthost.cidr
10.11.12.0/24 FILTER smtp:my.isp.smarthost
If you are using a content_filter, the setup is a little more
complicated... The check_recipient_mx_access table must be
defined in master.cf in the after-filter smtpd listener.
--
Noel Jones
