[Exim] Possible host list bug

We've noticed that mail from hosts with no reverse DNS registration is
rejected by exim when there is a host_reject_recipients directive with the
host list included from a file, even if the file contains only IP addresses.
This doesn't happen if an IP address is specified explicitly as the option
value. Prefixing with +allow_unknown does work, but my reading of the
documentation suggests that shouldn't be necessary. The behaviour is present
in exim 3.02 and 3.15.

Also, at least in test mode (exim -bh) it looks as if the DNS lookup is
being performed twice, once initially (in response to host_lookups) and then
again when the host list is evaluated. This doesn't seem very efficient!


John Holman
Head of Central Servers Team
Queen Mary and Westfield College
London, UK