Header Checks, examples?

Hey guys,

I was wondering if I could see some examples of various header check
implementations in Postfix. I've gone through the READMEs and from what
I've read, I'm not certain if I can do what I need to do in Postfix. Here's
what I need:

- Emails come all come into a server (hopefully a Postfix server)
- If a header is present (x-sa-scanned), do nothing (basically deliver the
email)
- If a header is *not* present (x-sa-scanned, of course) do the following
- Set the header
- Use transport to send it off to another server

So this is what I was thinking:

header_checks = regexp:/etc/postfix/header_checks

!/^x-sa-scanned/ FILTER smtp:[10.1.2.110]:25
!/^x-sa-scanned/ PREPEND X-SA-Scanned: 1\n\r

Unfortunately, it sounds like I can only trigger one of these at a time.
I'd actually like to scan another header (to) so that I could do this for
particular users as I work on this.

What would be the right way to do this?


Michael