[exim] 551 User not local; please try <forward-path>

Hi!

I'm trying to setup ~/.forward to generate this code on all delivery attempts:

551 User not local; please try <forward-path>

(551 is described in RFC 2821, 3.4)

I tried using the exim scripting language for ~/.forward, and crafted this:

# Exim filter
fail "551: User not local; please try <forward-path>"
finish

However, this generates an MDN which is not really what I want. If I understood
correctly, ~/.forward parsing happens before delivery, so we're still in time to
send this 551 code to the originator MTA.

Is there any way to generate the 551 code I need?

Thanks

--
Robert Millan