nanog mailing list archives
Re: Incoming SMTP in the year 2017 and absence of DKIM
From: Bjørn Mork <bjorn () mork no>
Date: Thu, 30 Nov 2017 18:55:18 +0100
Steve Atkins <steve () blighty com> writes:
On Nov 30, 2017, at 1:22 AM, Bjørn Mork <bjorn () mork no> wrote: "John Levine" <johnl () iecc com> writes:Broken rDNS is just broken, since there's approximately no reason ever to send from a host that doesn't know its own name.rDNS is not a host attribute, and will therefore tell you exactly nothing about the host.It tells you something about the competence of the operator and whether the host is intended by the owners to send email.
No. It only tells you something about the administrative split between IP address management and host management. There is no way my laptop is going to be able to update the rDNS for all addresses it will use in different networks. This does in no way affect its MTA configuration.
Or, for a more empirical way to look at it, there's reasonable correlation between having missing, generic or incorrect reverse DNS and the host being a source of unwanted or malicious email.
Really? Where did you get those numbers? This is a myth. Spam sources are average Internet hosts. The split between working and non-working rDNS is mostly between IPv4 and IPv6, not between ham and spam. And if there is some correlation there, then I'd say that an IPv4 host is more likely to be a spam source than a dual stack or IPv6 only host. Bjørn
Current thread:
- Re: Incoming SMTP in the year 2017 and absence of DKIM, (continued)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Grant Taylor via NANOG (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM John Levine (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Grant Taylor via NANOG (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM John Levine (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Grant Taylor via NANOG (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM John R. Levine (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Grant Taylor via NANOG (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Bjørn Mork (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Rich Kulawiec (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Steve Atkins (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Bjørn Mork (Dec 01)
- RE: Incoming SMTP in the year 2017 and absence of DKIM Keith Medcalf (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Owen DeLong (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Owen DeLong (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM John Levine (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Owen DeLong (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Grant Taylor via NANOG (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM John R. Levine (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM valdis . kletnieks (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM Owen DeLong (Dec 01)
- Re: Incoming SMTP in the year 2017 and absence of DKIM bzs (Dec 01)