Autor: David Woodhouse Data: Dla: Jan Johansson CC: David, exim-users, j2, Marc Perkel Temat: RE: [exim] check_helo_slow?
On Mon, 2005-01-10 at 13:31 +0100, Jan Johansson wrote: > > (Note that this is completely untested and it's Monday morning)
>
> If we look back to the original reason I did this.
>
> Is it a "fair" requirement that a MX should have a matching RDNS/HELO or
> am I to zealous? Sure, I have seen a few false positives, but over all,
> it seem to do the trick.
Only you can decide what 'too zealous' means for you, but you're
certainly more zealous than I'd want to be. You'd be rejecting some mail
from me because one of my MX hosts doesn't have correct reverse DNS at
the moment -- I request it occasionally but since it's hosted for free I
can't really complain too much :)
I don't think it makes sense to reject a connection solely for the crime
of having no rDNS, if the hostname used in HELO has an A or AAAA record
which points to the IP address of the connecting host, or if there's a
CSA record.
Even then, I suspect you'll see a bunch of false positives from idiot
Exchange users who can't even manage to get that much right. Only you
can decide how much you care :)