Re: [exim] User filters and headers

On Tue, Oct 18, 2005 at 11:25:05AM +0200, Warren wrote:
> Since "headers add" is not available to a user filter, is there any way
> i could add a custom header to a message that has been filtered by a
> users filter,
> without piping it to an external program to do the header addition?
> We are using the deliver function in the user filter but wish to add a
> custom header which can then be used on the remote side(s)
> to do the actual message delivery based upon this newly added header.

If I understood things right, the user filter runs with user privileges
and passes back a list of addresses to its parent running with
Exim privileges. The parent then starts deliveries for each address.
If the user filter modified the message, the change would be visible to
all recipients. That's why it can't do that.

This issue of modifying messages is a problem at various places.
Perhaps a proper copy-on-write solution is the answer, but that is not
going to happen any time soon, if at all.

Michael