I may have posted this at one point in the past, but I have a feature
request for host lists and I'm wondering if it would benefit others.
I maintain an emergency whitelist of sorts that contains IP addresses
of hosts that need to completely bypass all spam/sanity checks using a
regular Exim hostlist file, as in:
hostlist whitelist = EXIMDIR/whitelist
accept hosts = +whitelist
Here's the feature request. If I put in a hostname (instead of IP
address), Exim will stop processing the entire hostlist file if it
fails to look up a single hostname in that file due to a temporary DNS
lookup failure. This can happen if the remote DNS servers are
misconfigured (i.e. lame delegations) or if the remote site is having
problems.
Thing is, for a whitelist, I don't really care, and would prefer to
be able to add:
+ignore_defer
or something around the host names in that file. Perhaps it should be
called +ignore_again to match DNS terminology, or +ignore_errors to
indicate its ignoring *all* dns errors, rather than just permanent
failures.
You wouldn't want to use that option for configuration host files or
any other important list of hosts, but for something like this, it
makes perfect sense.
P.S. I know that reverse DNS hostnames can be spoofed, but with a
whitelist like this, I'm not concerned. It's just too difficult to
always track all the remote IP addresses associated with a domain or
hostname.
