[Exim] DNSBL: change of behaviour between Exim 3 and Exim 4

Hi,

Is there a cleaner way to get Exim 3 behaviour back in Exim 4, with regards
to the number of headers added for hosts that exist in more than one DNSBL?

For example, using this configuration in Exim 3:

rbl_domains = relays.ordb.org:relays.osirusoft.com:bl.spamcop.net:formmail.relays.monkeys.com
rbl_warn_header
no_rbl_reject_recipients

a mail would have N X-RBL-Warning: headers added, depending on how many of the
DNSBLs the connecting host was listed in, as per the Exim 3 spec:

| If a host appears in several RBL lists, more than one such header may
| be added to a message.

Under Exim 4, the following ACL would cause only one header (maximum) to be
added:

  warn    hosts       = +rbl_hosts
          message     = X-RBL-Warning: $sender_host_address is listed at $dnslist_domain
          dnslists    = relays.ordb.org:bl.spamcop.net:formmail.relays.monkeys.com

because, as per the Exim 4 spec:

| Testing the list of domains stops as soon as a match is found.

Is there a cleaner way to get Exim 3 behaviour back, with just one list of
DNSBL domains, than to have N ACL statements, one per DNSBL?

Thanks,

Ollie

--
Oliver Cook    Systems Administrator, Claranet UK
ollie@???                  020 7903 3000