IPv6-working freemail status

[Phil Pennock]

On 2010-01-14 at 23:09 +0100, Emanuele Balla wrote:
> At least some versions of Barracuda stuff out there seem to misparse
> Received headers and claim some random IPv6 address as blacklisted by
> ${RANDOM_DNSBL}.

On exim-users, there's been at least one report that an IPv6 address put
into a DNSxL lookup, following the correct nibble rules, results in the
DNSxL server returning false positives.

I believe that it was rbldnsd which was broken but am not completely
sure.

The workaround is easy, you just only permit DNSxL lookups for IPv4
addresses and implicitly whitelist IPv6; not a long-term solution,
obviously.  (condition = ${if isip4{$sender_host_address}}).

-Phil