nanog mailing list archives

Re: IPv6 isn't SMTP


From: "rwebb () ropeguru com" <rwebb () ropeguru com>
Date: Wed, 26 Mar 2014 09:05:52 -0400

On Wed, 26 Mar 2014 07:45:06 -0500
 Daniel Taylor <dtaylor () vocalabs com> wrote:
On 03/25/2014 11:18 PM, John Levine wrote:
3. Arguing about IPv6 in the context of requirements upon SMTP connections is playing that uncomfortable game with
one�s own combat boots.  And not particularly productive.
If you can figure out how to do effective spam filtering without
looking at the IP addresses from which mail arrives, you will be in a
position to make a whole lot of money.

But, as always, I'm not holding my breath.

R's,
John

PS: Note the word "effective".

You look at the IP, and verify forward and reverse DNS.

IPv6 doesn't make this any harder a problem than IPv4, it just means that we're going to *have* to reject mail that comes in from IPv6 addresses that don't have clean DNS.

--
Daniel Taylor VP Operations Vocal Laboratories, Inc. dtaylor () vocalabs com http://www.vocalabs.com/ (612)235-5711



Actually, with all the discussion about ipv6 not having rDNS, in most cases, would that not make things easier? So those that want to run email servers SHOULD be on ISP's that allow for rDNS configuration for IPv6. There should be some vetting in the process by the ISP, maybe, before allowing this. So in essence, if you are a legitimate email host, you will have rDNS configured on IPv6 for your server. Again, as others have stated, rDNS should NOT be the only deciding factor in whether or not an email is legit. No rDNS, or havinf rDNS, should have some weight assigned to it for the overall evaluation of the sender.

Robert


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