Hello!
I have exim 3.03 configured with host_lookup = 0.0.0.0/0 and a list of
special hosts from which no mail may be sent (host_reject_recipients).
If I get it right, either of the two above options causes exim to try to
resolve the IP address of a connecting host to a name. This is indeed
what I want but if this lookup fails, the message is rejected
completely. There are some hosts sending mail to us whose IP adress has
obviously no PTR record anywhere, and there are also some that get
resolved into a name but the name cannot be resolved back into an IP
address. Exim rejects this mail then as well.
I don´t know if I should consider these hosts (resp. their DNS) as
misconfigured so they don´t deserve to be sending mail to us - this
seems a bit strange.
How should I get by this? I can´t find an option that causes Exim to
skip this test, so shall I leave it as it is?
I don´t use tcpwrappers for Exim.
Hints appreciated,
Tobias