Thank you very much for the detailed explanation Wietse, it makes more sense to me now re: the order of operations.
Cheers, VM On Aug 21, 2014 5:31 AM, "Wietse Venema" <wie...@porcupine.org> wrote: > Venkat: > > What I am trying to do is: > > > > Setup a SMTP relay for outgoing mail where: > > (a) All From: headers of the form u...@cooldomain1.com (example) are > > rewritten to be no-re...@cooldomain2.com > > (b) A Reply-To: header with the original u...@cooldomain1.com is added > > > > I have achieved this by using this combination: > > -- using sender_canonical_maps set to: > > @cooldomain1.com no-re...@cooldomain2.com > > -- using header_checks set to: > > /^From: (.*@cooldomain1\.com)/ PREPEND Reply-To:$1 > > > > This seems to work. However, I am not sure if this is a good > > approach or would using a milter (FILTER action in header_checks) > > be a better way? If so, is there a pre-existing milter available > > for this that is recommended? Thanks all. > > Your configuration should be safe, if I read Postfix documentation > carefully. Remember, undocumented Postfix behavior is not covered > by any promise of future compatibility. > > The header_checks manpage promises that PREPENDed text is not subject > to header_checks or address rewriting, and that it does not affect > the way that Postfix adds missing message headers. So this part > of your design is safe. > > Does Postfix documentation promise that header_checks happen before > address rewriting? It makes that promise in a non-obvious manner. > > The text for the "REPLACE" action says that the replacement text > will be subject to address rewriting (among other things). This > suggests that header_checks happen before address rewriting. > > So there is an implicit promise that header_checks happen before > address rewriting. This order should probably be documented, along > with the relative timing of Milter activity. > > Wietse >
