On 9/23/2014 2:31 PM, Michael Fox wrote: > Sanity check please: > > > > I have a relay machine: relay.domain1.com > > And a client: client.domain2.com > > > > I’d like to filter (silently discard) messages at the relay machine > from going to any account on the client machine if the From: address > is: groupsupda...@yahoogroups.com > <mailto:groupsupda...@yahoogroups.com>. But such messages going to > accounts on the relay machine are o.k. > > > > So, is it correct that I could use something like this: > > > > main.cf: > > smtp_header_checks = pcre:/etc/postfix/smtp_header_checks.pcre > > > > smtp_header_checks.pcre: > > /^From: .*groupsupda...@yahoogroups.com.*/ > <mailto:.*groupsupda...@yahoogroups.com.*/> DISCARD optional-log-text > > >
No, smtp_header_checks cannot change a message destination (ie. discard instead of deliver). Note filtering on the From: header is generally wrong, use the envelope sender instead. And it's generally considered bad to DISCARD messages; mail shouldn't disappear except under extraordinary circumstances. What you can do is create a restriction class to check the sender and the recipient, and reject the message if both match. The general procedure is outlined here, with some examples similar to what you're asking: http://www.postfix.org/RESTRICTION_CLASS_README.html Alternately, you can use a policy service such as postfwd to reject mail with a combination of sender and recipient. http://www.postfix.org/SMTPD_POLICY_README.html http://postfwd.org/ -- Noel Jones
