* Vance Gloster <glosterva@???> [2004-11-02 23:07]:
>
> You need to prepend a header to the entire message that contains a
> digital signature. I have the code to calculate the signature. I'm
> just curious about the best way to insert it into the header above all
> the other headers. The normal system filter header commands insert
> headers after all the other headers.
Maybe this new feature is of any use for this?
IIRC it was introduced for exactly such new techniques as
SPF or Domainkeys.
-> NewStuff for Exim 4.43
4. When an ACL "warn" statement adds one or more header lines to a message,
they are added at the end of the existing header lines by default. It is
now possible to specify that any particular header line should be added
right at the start (before all the Received: lines) or immediately after
the first block of Received: lines in the message. This is done by
specifying :at_start: or :after_received: (or, for completeness, :at_end:)
before the text of the header line. (Header text cannot start with a colon,
as there has to be a header name first.) For example:
warn message = :after_received:X-My-Header: something or other...
If more than one header is supplied in a single warn statement, each one is
treated independently and can therefore be placed differently. If you add
more than one line at the start, or after the Received: block, they will
end up in reverse order.
Warning: This facility currently applies only to header lines that are
added in an ACL. It does NOT work for header lines that are added in a
system filter or in a router or transport.
Dominik
