[exim] Is it possible to reject message at DATA ACL but real…

Hi.

I have a lot of e-mail addresses (non-local for Exim) that are generated
for "short-term objectives".

So after a lapse of time they become "invalid" - and sender *should*
receive 5xx error when he tries to send e-mail to such addresses
(something like "550 - this address is invalid now, please send e-mail to
support@.... for further information.").

But I want this e-mail *to be delivered* to some other address for further
analysis - e.g., to "all_invalid_temporary_addresses@....".


The main idea is that this e-mail *may be still useful* for us but sender
*should never use* this address hereafter.


Here is how I do it now:

1) tag such e-mail with acl variable at DATA acl;

2) set 1st router to add a recipient
"all_invalid_temporary_addresses@...." to tagged e-mail;

3) set 2nd router to fail on tagged e-mail when recipient addresses are
differed from "all_invalid_temporary_addresses@....".

But this configuration causes a damned backscatter problem (SMTP session is
completed successfully and later Exim sends NDR to sender) :-(((


So is it possible to reject such message *exactly* during SMTP session but
really deliver it? Or is there any other solution?

Thanks in advance,

Vitas.