[Exim] recipients in system filter

Hi!

Is there any way to handle several recipients of a mail differently
from within a system filter?

To have some control of which users can send to non-local domains, a
system filter could be set up as follows:

[...]
# block mail to non-local users from local users according to setup
#
if ${lookup{$sender_address:out}lsearch{/etc/exim/mail.allow}{$value}} is "no" then
  if foranyaddress $recipients ($thisaddress does not contain "yun.yagibdah.de") then
    fail "\nSorry, you're not allowed to send mail\n\
          to non-local users like <$thisaddress>.\n\
          This has been configured by the system\n\
          administrator.\n"
  endif
endif
[...]

The filter looks up users in /etc/exim/mail.allow. That file contains
a list of users for whom restrictions should apply:


lee@???: in=yes out=no
foo@???: in=yes out=no


In this example, both lee and foo are restricted from sending mail to
non-local domains. This works until they create messages with multiple
recipients: all recipients would fail. But I want the message
delivered to those recipients that are local and rejected for those
that are remote.

How can I achieve that?

BTW, the filter file should exclude bounces from being rejected. How
can I put the empty string into filter files?


GH
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