> On 4/4/2011 9:54 PM, email builder wrote: > > > > OK, sorry again. I had assumed because you can turn off header checking by > > using receive_override_options, you could also override (change) them. > > It is possible to override header_checks by defining a different >cleanup_service_name > for smtpd, then defining that cleanup service with a header_checks override. > >This > can get pretty messy, you can find examples in the list archives.
Mmm, thanks. I just happened to find this idea late yesterday when researching this issue. It's interesting, but it looks like it ultimately isn't necessary. > The better solution is to use multiple instances. All postfix versions >support multiple > instances. Newer versions include tools to make multiple instance >creation/maintenance > easier. I've been trying to avoid this, but we might end up having to go this route. Thanks for the encouragement. > > Reading smtpd(8) manpage, it does seem like smtpd_data_restrictions would > > be >a > > good place to be able to inspect the mail headers and use the PREPEND to >insert > > a new header. But I was using check_client_access to do so, and that only >seems > > to inspect the client address and related information.... but looking >through > > the list of restrictions I cannot understand which one allows the > > inspection >of > > the message data itself. > > The postfix smtpd_*_restrictions allow you to inspect envelope information. > > To inspect message header or body contents, postfix provides header_checks, > body_checks, and an interface for an external content filter, proxy, or >milter. > http://www.postfix.org/CONTENT_INSPECTION_README.html This jives with what I'd understood from the documentation - smtp_*_restrictions let you check the envelope only, not the headers/body. But I was confused by some people giving examples of how to add headers with PREPEND actions during some smtpd_*_restrictions checks. It turns out (from my testing, but I can't find this in the docs) that you can still use PREPEND to add a header even though you're looking at certain envelope data. The other confusing bit was what to test for -- since you're looking at the envelope, you can't just look for /^From:/ for example. It's not there. But since I'm trying to unconditionally add a header, the trick seems to be that what's there does not matter (just use /^/), and in that sense, the envelope check for, say, sender, is perfect - it's just one line (so your header doesn't get added more than once). So all you have to do is: master.cf smtpd process entry: -o smtpd_data_restrictions=check_sender_access,pcre:/etc/postfix/add_my_header /etc/postfix/add_my_header: /^/ PREPEND X-My-Header: Hello_world Easier than I thought. Now, PLEASE don't take this the wrong way, but I'm wondering why no one offered this solution. Am I doing something I should not be doing?
