On Sep 21, 2013, at 15:24, "Jan P. Kessler" <post...@jpkessler.info> wrote:
> Am 21.09.2013 15:17, schrieb Jan P. Kessler: >>> Would the single, existing instance with 'smtp_header_checks' not >>> achieve the same thing? >>> >>> http://www.postfix.org/postconf.5.html#smtp_header_checks >> >> Not, if the required headers are added later on by a content_filter. > > Just to be clear. What I meant was: > > - postfix-1 accepts mail and some spamfilter (pre- or postqueue) scans > and adds headers. > - mail gets delivered locally > - forwarded (non-local) mail is sent to postfix-2 instance (relayhost) > - mail with "x-spam-flag: yes" get's discarded/redirected by header_checks > - other mail is forwarded to gmail/yahoo/whatever I understand what you mean, but I am not a big fan of adding complexity if it is not absolutely necessary. Especially when it comes to discarding mail based on 'header_checks', as those apply to incoming messages as well; the 'x-spam-flag: yes' is a fairly universally used header, after all. One could of course add a custom header unique to the system, but I would much prefer to handle it locally, in a single instance, preferably from within the content filtering software itself. Mail server setups tend to live for a long time, and one might not remember why the DISCARD was there, reuse the header for another purpose, create a mail loop because the relayhost redirects to a mailbox local to the first instance, that someone puts an external redirect on because the system is running out of space two years down the line, etcetera, etcetera. Keeping it local, preferably within the same 'step' within the delivery workflow that scores your spam, tends to be the most robust. Mvg, Joni
