As of today I count 168708 domains with correct DANE TLSA records for SMTP. As expected the bulk of the DANE domains are hosted the handful of DNS/hosting providers who've enabled DANE support in bulk for the domains they host. The top 10 MX host providers by domain count are:

69372 domeneshop.no 58498 transip.nl 18224 udmedia.de 6769 bhosted.nl 1824 nederhost.net 993 ec-elements.com 494 core-networks.de 365 networking4all.net 337 bit.nl 328 omc-mail.com

The real numbers are surely larger, because I don't have access to the full zone data for most ccTLDs. However, this month, I was able to obtain nearly comprehensive domain lists for .no, .nl and .de, which accounts for the unusually large increase over the previous month's totals.

There are 2529 unique zones in which the underlying MX hosts are found, this counts each of the above providers as just one zone, so is a measure of the breadth of adoption in terms of servers deployed. Alternatively, a similar number is seen in the count (2644) of distinct MX host server certificates that support the same ~168000 domains.

A related number is 3795 TLSA RRsets found for MX host TCP port 25. This includes secondary MX hosts and domains none of whose primary MX hosts have TLSA records.

The number of domains that at some point were listed in Gmail's email transparency report is 105 (this is my ad-hoc criterion for a domain being a large-enough actively used email domain). Of these, 53 are in recent reports (April 2017):

gmx.at jpberlin.de bhosted.nl nic.br lrz.de ouderportaal.nl registro.br mail.de overheid.nl gmx.ch posteo.de pathe.nl open.ch ruhr-uni-bochum.de xs4all.nl anubisnetworks.com tum.de domeneshop.no gmx.com uni-erlangen.de webcruitermail.no mail.com unitymedia.de debian.org solvinity.com web.de freebsd.org t-2.com enron.email gentoo.org trashmail.com octopuce.fr ietf.org xfinity.com comcast.net isc.org nic.cz dd24.net netbsd.org bayern.de gmx.net openssl.org bund.de hr-manager.net samba.org elster.de t-2.net torproject.org fau.de xs4all.net asf.com.pt gmx.de asp4all.nl

Of the ~168000 domains, 737 have "partial" TLSA records, that cover only a subset of the MX hosts. While this protects traffic to some of the MX hosts, such domains are still vulnerable to the usual active attacks via the remaining MX hosts.

The number of domains with incorrect TLSA records or failure to advertise STARTTLS (even though TLSA records are published) stands today at 73 (~10 are recent additions that may be resolved soon, the remaining ~60 are the for now stable population of broken domains). This month I'm posting the list of the 40 underlying MX hosts that serve these domains and whose TLSA records don't match reality.

Hall of Shame:

mail.dipietro.id.au mx.quentindavid.fr mail.jekuiken.nl mail.pgp.inf.br servmail.fr mail.myzt.nl mail.digitalwebpros.com mail.nonoserver.info bounder.steelyard.nl demo.liveconfig.com mail.laukas.lt mx.wm.net.nz ny-do.pieterpottie.com mx.datenknoten.me kitsune.one diablo.sgt.com mx.giesen.me baobrien.org tusk.sgt.com mail.castleturing.net beerstra.org mx.bels.cz datawebb.dafcorp.net smtp.copi.org mail.enzevalos.de anubis.delphij.net eumembers.datacentrix.org mail.manima.de dorothy.goldenhairdafo.net smtp3.amadigi.ovh www.mtg.de hs.kuzenkov.net protector.rajmax.si mx1.spamsponge.de oostergo.net email.themcintyres.us gamepixel.eu ren.warunek.net mail.thomspooren.eu mail.e-rave.nl

The number of domains with bad DNSSEC support is 263. With axc.nl (the previous #1) resolved this month, the top 13 DNS providers with problem domains, after a 5-way tie for 8th place are:

37 infracom.nl - Was slated to be resolved in March, delayed... 18 loopia.se 18 active24.cz 14 jsr-it.nl 13 rdw.nl 9 cas-com.net 8 metaregistrar.nl 6 tiscomhosting.nl 6 pfsc.com 6 ovh.net

Around 50 of the broken domains have at least one working nameserver, and so are email-reachable, given enough retries. Only 6 of these DNS-broken domains appear in historical Google Email transparency reports:

tjce.jus.br trt1.jus.br trtrj.jus.br tse.jus.br amsterdam.nl rzd.ru

The associated DNS lookup issues are:

_25._tcp.ims1.rzd.ru. IN TLSA ? ; TLSA non-response: http://dnsviz.net/d/_25._tcp.ims1.rzd.ru/dnssec/ _25._tcp.ims2.rzd.ru. IN TLSA ? ; TLSA non-response: http://dnsviz.net/d/_25._tcp.ims2.rzd.ru/dnssec/ _25._tcp.lalavava.tse.jus.br. IN TLSA ? ; TLSA non-response: http://dnsviz.net/d/_25._tcp.lalavava.tse.jus.br/dnssec/ _25._tcp.mx1.trt1.jus.br. IN TLSA ? ; zone signature failure: http://dnsviz.net/d/_25._tcp.mx1.trt1.jus.br/dnssec/ _25._tcp.mx1.trtrj.jus.br. IN TLSA ? ; zone signature failure: http://dnsviz.net/d/_25._tcp.mx1.trtrj.jus.br/dnssec/ _25._tcp.mx2.tjce.jus.br. IN TLSA ? ; SOA signature failure: http://dnsviz.net/d/_25._tcp.mx2.tjce.jus.br/dnssec/ _25._tcp.mxin1.amsterdam.nl. IN TLSA ? ; TLSA non-response: http://dnsviz.net/d/_25._tcp.mxin1.amsterdam.nl/dnssec/

[ See https://tools.ietf.org/html/draft-ietf-dnsop-no-response-issue-08, Much of the TLSA non-response issue seems to be related to a "feature" of Arbor Networks firewalls, that enables droping of DNS requests for all but the most common RRtypes. Do not make the mistake of enabling this firewall "feature". ]

The oldest outstanding DNS issue is another SOA signature issue at truman.edu dating back to Nov/2014:

http://dnsviz.net/d/_25._tcp.barracuda.truman.edu/VGzORw/dnssec/

I hope some day soon they'll start missing email they care about and take the time to resolve the problem.