Long-tail of email infrastructure — 2026-09-10

Deep-dive into the Unknown / Generic MX bucket — the deliverability reality outside the Google / Microsoft monoculture.

At a glance

Unknown / Generic11.20%74 737 domainsUnique unmatched MX35 882individual hostnamesSelf-hosted22.49%150 010 domains

What is this report?

Most landing-page summaries focus on the head of the distribution — Google Workspace, Microsoft 365, Yandex 360. About one in four domains in the Tranco top-1M lives outside that head: regional hosters, self-built Postfix/Exim, niche ESPs, corporate on-prem gateways. This is where most deliverability surprises actually happen. This page surfaces the raw long-tail so security researchers, deliverability teams and dictionary maintainers can mine it.

Top 1000 most common unmatched MX hosts

Sorted by number of domains using each. This is the practical feed-list — every entry near the top is a candidate for inclusion in our dictionaries/mx_providers.py. CSV download covers all 1000.

#	MX target	Domains
1	mail.levikof.com	995
2	localhost	420
3	mail	242
4	mail.parktons.com	176
5	mail1.sbnation.com	165
6	alltheemails.com	140
7	mail.pickelhost.com	138
8	mx.email-messaging.com	135
9	ms06.cv-library.co.uk	133
10	ms07.cv-library.co.uk	133
11	ms08.cv-library.co.uk	133
12	ns4.forevermail.com	131
13	lbmx.bcc.gov.bd	128
14	s.mail.dcsaas.net	128
15	mail2.recop.jp	126
16	mail.autoline.com.ua	119
17	mx2.z-ns.net	118
18	mxi.alpha-prm.jp	115
19	mx1d10.thinline.cz	111
20	mx1b20.thinline.cz	111
21	mx1.ticketsinbound.com	105
22	mail.mpcloud.net	104
23	mx2.ticketsinbound.com	102
24	mx.maxns.net	94
25	mx-backup.serveriai.lt	93
26	~	91
27	mail-fr.securemail.pro	91
28	mx.aams4.jp	90
29	mx2.netim.net	89
30	townsites.dnsmaster.net	89
31	mx1.netim.net	88
32	mx-0.aams4.jp	87
33	mx-1.aams4.jp	87
34	cloudmail.auto-vision.ru	85
35	amazon-smtp.amazon.com	85
36	mail.vipmailservice.com	82
37	mailforward.dnsv.jp	80
38	mx-01.mail-forwarder.io	80
39	mailgw01.host.it	79
40	mx-02.mail-forwarder.io	78
41	mailgw02.host.it	77
42	mx1.email-cluster.com	77
43	mx2.email-cluster.com	77
44	mx.vshosting.eu	77
45	mx1-dk.centerasecurity.dk	76
46	mx2-dk.centerasecurity.dk	76
47	failover1.email-cluster.com	75
48	mx6.kvnbw.de	74
49	mx7.kvnbw.de	74
50	mx8.kvnbw.de	74

Show rows 51 – 1000

#	MX target	Domains
51	mx9.kvnbw.de	74
52	posta.mediacenter.hu	70
53	posta2.mediacenter.hu	70
54	posta4.mediacenter.hu	70
55	posta5.mediacenter.hu	70
56	mx3-dk.centerasecurity.dk	70
57	mail.global.frontbridge.com	70
58	email.webglobe.cz	70
59	email2.webglobe.cz	70
60	q01es.mail.s-web.de	70
61	q02es.mail.s-web.de	70
62	r01es.mail.s-web.de	70
63	r02es.mail.s-web.de	70
64	posta3.mediacenter.hu	69
65	email3.webglobe.cz	69
66	email4.webglobe.cz	69
67	mx01.muumuu-mail.com	68
68	mxa.expediagroup.com	67
69	mxb.expediagroup.com	67
70	mail.bluetie.com	66
71	mx1.oderland.com	66
72	mx2.oderland.com	66
73	gmail22.gadmail.de	66
74	gmail23.gadmail.de	66
75	wmail22.gadmail.de	66
76	mx.sendcloud.org	65
77	smtp.faisco.cn	65
78	wmail23.gadmail.de	65
79	mta.vshosting.eu	64
80	mx1.mgn.net	64
81	mx4.emailowl.com	63
82	mx2.mgn.net	63
83	mx3.mgn.net	63
84	mx1.nepal.gov.np	63
85	smtp-avas.seeweb.it	62
86	mx1.daouoffice.com	62
87	mx01.statens-it.dk	62
88	mx02.statens-it.dk	62
89	mx03.statens-it.dk	62
90	mx04.statens-it.dk	62
91	mx05.statens-it.dk	62
92	mx06.statens-it.dk	62
93	mx07.statens-it.dk	62
94	mx08.statens-it.dk	62
95	rmail22.gadmail.de	62
96	rmail23.gadmail.de	62
97	mx2.nepal.gov.np	62
98	mx3.oderland.com	61
99	mx4.oderland.com	61
100	mx5.emailowl.com	61
101	mx1.simplelogin.co	61
102	mx2.simplelogin.co	61
103	mx4.nameshield.net	61
104	omail22.gadmail.de	61
105	omail23.gadmail.de	61
106	d01es.mail.s-web.de	61
107	d02es.mail.s-web.de	61
108	e01es.mail.s-web.de	61
109	e02es.mail.s-web.de	61
110	mx.spamfilter.io	60
111	mx6.emailowl.com	60
112	void.blackhole.mx	60
113	antispam.tebilisim.com	58
114	mx1.alwaysdata.com	58
115	mx2.alwaysdata.com	58
116	generalsmtp.disney.com	56
117	mx.mymailwall.com	56
118	mx2.daouoffice.com	55
119	mrelay2.axa.com	55
120	c1.liara.email	54
121	mx01.cbsolt.net	54
122	mx02.cbsolt.net	54
123	spamexpert01.host.bg	54
124	spamexpert02.host.bg	54
125	mxwcom.263xmail.com	53
126	mx-mibc-fr-11.mailinblack.com	53
127	antispam.korea.kr	53
128	mxcom.263xmail.com	52
129	mx-1.mail.go.id	52
130	mx-2.mail.go.id	52
131	mx-n.global-mail.cn	52
132	p.webcom.ctmail.com	51
133	cloudmail01.clausweb.ro	51
134	cloudmail02.clausweb.ro	51
135	cloudmail03.clausweb.ro	51
136	cloudmail04.clausweb.ro	51
137	mx-3.mail.go.id	51
138	mx-4.mail.go.id	51
139	mx1.netsolmail.net	51
140	g01es.mail.s-web.de	51
141	g02es.mail.s-web.de	51
142	z01es.mail.s-web.de	51
143	z02es.mail.s-web.de	51
144	adresseavisen.in.tmes.trendmicro.eu	50
145	mx01.easyname.eu	50
146	mx02.easyname.eu	50
147	mx10.active24.cz	49
148	mx20.active24.cz	49
149	ni-spamexperts.guzel.net.tr	49
150	mx1.mythic-beasts.com	49
151	mx2.mythic-beasts.com	49
152	mx.otenet.gr	49
153	mx2.mijndomein.nl	49
154	mx01.glesys.se	49
155	mail.twincdn.com	49
156	entrap-01.hostns.io	48
157	entrap-02.hostns.io	48
158	entrap-03.hostns.io	48
159	mail1.no-ip.com	48
160	mail2.no-ip.com	48
161	mx1.mijndomein.nl	48
162	semail.sandhills.com	48
163	wemail.sandhills.com	48
164	mx1.pokingbear.com	48
165	mail.univalence.com	48
166	mail.mailhub.work	47
167	mx1.daringibex.com	47
168	smtp-scan01.mx.reflected.net	47
169	mail02.mail-gw.de	47
170	mail03.mail-gw.de	47
171	mx4.otenet.gr	46
172	mx2.postmaster.hu	46
173	mx1.loading.es	46
174	mx2.loading.es	46
175	mx3.loading.es	46
176	mx2.otenet.gr	46
177	mx1.bund.de	46
178	mx1.krystal.io	45
179	mx2.krystal.io	45
180	mail.gigaserver.cz	45
181	a1.spambusters.email	45
182	n1.spambusters.email	45
183	mx2c51.megamailservers.eu	45
184	mx2.bund.de	45
185	mxc.global-mail.cn	45
186	mx1-n.global-mail.cn	44
187	y01es.mail.s-web.de	44
188	y02es.mail.s-web.de	44
189	mxpool.de2.hostedoffice.ag	44
190	mx.stable.cz	44
191	mx3.otenet.gr	44
192	mail.idp365.net	44
193	relay.exohosting.sk	44
194	mxu.global-mail.cn	44
195	mail1.digikey.com	44
196	mail2.digikey.com	44
197	mail3.digikey.com	44
198	mx1.supremebox.com	43
199	mx02.glesys.se	43
200	mx1.tigertech.net	42
201	mx2.tigertech.net	42
202	mx3.tigertech.net	42
203	mx2.supremebox.com	42
204	mx01.ergonet.it	42
205	mx02.ergonet.it	42
206	mx03.ergonet.it	42
207	mx04.ergonet.it	42
208	mx2.smtp.goog	42
209	mx3.smtp.goog	42
210	mx4.smtp.goog	42
211	mars.intermailgate.com	42
212	mx1.1984.is	41
213	mail1.correo.gob.es	41
214	mail2.correo.gob.es	41
215	mx.noris.net	41
216	mx1.smtp.goog	41
217	relay2.dnsserver.eu	41
218	mail.variomedia.de	41
219	mx2.1984.is	40
220	mx1.daemonmail.net	40
221	mx2.daemonmail.net	40
222	mx.stable.sk	40
223	mail.valtori.fi	40
224	mx2.us.opalstack.com	40
225	mx1.us.opalstack.com	40
226	inbound.postmarkapp.com	40
227	smtp-in-internet-usr-m.gslb.srv.bnpparibas	40
228	relay1.exohosting.sk	40
229	relay3.dnsserver.eu	40
230	webmail3.terrawan.eu	40
231	mxs.ht-systems.ru	40
232	mail-in.fruugo.net	40
233	mx1.emailowl.com	39
234	mx.siteprotect.com	39
235	mail.bayern.de	39
236	mx01.tophost.ch	39
237	mx-mibc-fr-06.mailinblack.com	39
238	mail.mizbanfalocal.com	39
239	mxmail.icoremail.net	38
240	mx1.friendfinder.com	38
241	mx2.friendfinder.com	38
242	mx3.friendfinder.com	38
243	mt-spamexperts.guzel.net.tr	37
244	eu-esec-01.heimdalsecurity.com	37
245	eu-esec-02.heimdalsecurity.com	37
246	mx.easymail.ca	37
247	mail2.careerjet.net	37
248	mx01.routing.net	37
249	mx03.routing.net	37
250	1-grid-mx02.com	36
251	1-grid-mx03.co.za	36
252	1-grid-mx01.co.za	36
253	mx1.webhouse.sk	36
254	mx2.webhouse.sk	36
255	mx3.webhouse.sk	36
256	fakemx.noris.net	36
257	mx2.emailowl.com	36
258	mx3.emailowl.com	36
259	mx02.tophost.ch	36
260	mx.noris.de	36
261	mx-mibc-fr-07.mailinblack.com	36
262	mail.swisscom.com	36
263	mail10.swisscom.com	36
264	mail20.swisscom.com	36
265	mx.buzondecorreo.com	36
266	mx.cstnet.cn	36
267	mx02.routing.net	36
268	mx2.pokerstars.com	36
269	1-grid-mx04.com	35
270	mail3.makeshop.jp	35
271	mx100.ucozmail.com	35
272	mail4.makeshop.jp	35
273	mx.zohocloud.ca	35
274	mxs.armgs.team	35
275	mx1.mas.t-systems-service.com	35
276	france.security-mail.net	35
277	europe.security-mail.net	35
278	mail73.conoha.ne.jp	35
279	mg.g-cloud.by	35
280	mx.renr.es	35
281	mx10.websupport.se	35
282	mx01.shopmania.biz	35
283	pri-jeemsg.eemsg.mail.mil	35
284	sec-jeemsg.eemsg.mail.mil	35
285	mx1.mailer91.com	34
286	mail.techsurgeons.com	34
287	mx.soverin.net	34
288	mail.mystoredns.com	34
289	mx2.zohocloud.ca	34
290	mx3.zohocloud.ca	34
291	mx2.mas.t-systems-service.com	34
292	mx3.mas.t-systems-service.com	34
293	mmx.mail.gov.az	34
294	mail-pt.securemail.pro	34
295	mx20.websupport.se	34
296	gatekeeper.space.net	34
297	mail.lakennetwork.com	34
298	mx0002.neo.space	34
299	mx0001.neo.space	34
300	mail.nhs.uk	34
301	mx1.antispam-login.net	34
302	mx2.antispam-login.net	34
303	zc-mx.zohocorp.com	34
304	zc-mx2.zohocorp.com	34
305	zc-mx3.zohocorp.com	34
306	mailbox.wargaming.net	34
307	eu1-smtp-mx1.titanhq.com	33
308	mx1.maileroo.com	33
309	mx2.mailer91.com	33
310	ntvirus.url.com.tw	33
311	ntvirus2.url.com.tw	33
312	mx-10.au-east.atmailcloud.com	33
313	mx-20.au-east.atmailcloud.com	33
314	mail2.mystoredns.com	33
315	mx1.nz.smxemail.com	33
316	mx1.dnsmadeeasy.com	33
317	mx2.dnsmadeeasy.com	33
318	assur.rtl.de	33
319	marduk.rtl.de	33
320	sul.rtl.de	33
321	sulis.rtl.de	33
322	smtp-avas-th.seeweb.it	33
323	gatekeeper.spacenet.de	33
324	mx0.mail7.freehost.com.ua	33
325	mx1.mail7.freehost.com.ua	33
326	mx2.mail7.freehost.com.ua	33
327	mail-8.mtpserver.net	33
328	mail-12.mtpserver.net	33
329	mail-13.mtpserver.net	33
330	mx.x.recruit.co.jp	32
331	email.imcloud.org	32
332	mxin1.airnet.ne.jp	32
333	mxin2.airnet.ne.jp	32
334	mx.getcourse.ru	32
335	mail.joker.com	32
336	mrelay.axa.com	32
337	inbound01.dynata.com	32
338	inbound02.dynata.com	32
339	inbound03.dynata.com	32
340	mail.cmposta.com	32
341	alt2-mx.rackhostmx.com	32
342	mx.ms.bi.zone	32
343	eu1-smtp-mx2.titanhq.com	31
344	mx2.maileroo.com	31
345	mg1.g-cloud.by	31
346	mail.postale.io	31
347	mx0.fortion.net	31
348	mx3.dnsmadeeasy.com	31
349	pmg.prodestek.com.tr	31
350	mxs.activeby.net	31
351	mforward.dtag.de	31
352	mx1.alibaba-inc.com	31
353	mx1.fiercebadger.com	31
354	smtp.dvtech.io	31
355	mx01.ntc.net.pk	31
356	mail.makeup.com.ua	31
357	wmx.ecounterp.com	30
358	mx.fimn.net	30
359	mx-mibc-fr-08.mailinblack.com	30
360	mx1.fortion.net	30
361	cnc.biz-email.net	30
362	mmxs.majordomo.ru	30
363	mx2.nz.smxemail.com	30
364	mail.websitefa.com	30
365	mx.zoho.jp	30
366	mx2.zoho.jp	30
367	mx3.zoho.jp	30
368	mx01.agnat.pl	30
369	mail2.filteredmx.net	30
370	mx.mailo.com	30
371	mx.serveriai.lt	30
372	mx.claramail.com.br	30
373	email.cnhi.com	30
374	smtp.renault.fr	30
375	smtp2.renault.fr	30
376	mxbackup.routing.net	30
377	mx1.ravingchamois.com	30
378	a2.spambusters.email	30
379	mx.mailbox.orange-business.com	30
380	mx1c51.megamailservers.com	30
381	mx10.vwgroup.com	30
382	aspmx1.dooray.com	30
383	sgc.hsplus.email	30
384	us1-smtp-mx1.titanhq.com	30
385	mail-relay.wetteronline.de	30
386	ssl.emailserver.vn	29
387	mx2.fortion.net	29
388	mail1.ethionet.et	29
389	mail2.ethionet.et	29
390	mail3.ethionet.et	29
391	mail4.ethionet.et	29
392	mx-waw.grupawp.pl	29
393	mx-gda.grupawp.pl	29
394	mx.truemail.it	29
395	mail1.filteredmx.net	29
396	mail3.filteredmx.net	29
397	mx02.emailpnl.com	29
398	mx3c51.megamailservers.com	29
399	us1-smtp-mx2.titanhq.com	29
400	mail.cm.telia.net	29
401	mx-mibc-fr-10.mailinblack.com	28
402	mx4.webhouse.sk	28
403	mx5.webhouse.sk	28
404	mx6.webhouse.sk	28
405	a.mx.mayfirst.org	28
406	b.mx.mayfirst.org	28
407	c.mx.mayfirst.org	28
408	mail.biz-email.net	28
409	eagle.mxlogin.com	28
410	mx1.earfulwolf.com	28
411	inmx.rambler-co.ru	28
412	mx1.dfw.automattic.com	28
413	mx2.ams.automattic.com	28
414	mx3.34sp.com	28
415	mx-dor.bell.ca	28
416	mx-wyn.bell.ca	28
417	reply.s12.exacttarget.com	28
418	mailgw.nic.in	28
419	mx01.emailpnl.com	28
420	mailin100.dcpserver.de	28
421	mail.med-vergleich.com	28
422	rmx.mailgw.jp	28
423	sgrmgw5.swatchgroup.com	28
424	sgrmgw6.swatchgroup.com	28
425	mx1-mailcontrol.conova.com	28
426	mx2-mailcontrol.conova.com	28
427	mx3-mailcontrol.conova.com	28
428	mx4-mailcontrol.conova.com	28
429	mx1.dandomain.dk	28
430	mailasp.sovcombank.ru	28
431	dmeas13.imail.scig.gov.hk	28
432	dmeas14.imail.scig.gov.hk	28
433	pmeas13.imail.scig.gov.hk	28
434	pmeas14.imail.scig.gov.hk	28
435	corpmx.yelpcorp.com	28
436	mx.online.net	27
437	work-mx.app.hey.com	27
438	securemail-mx1.synaq.com	27
439	securemail-mx2.synaq.com	27
440	mx1.krystal.co.uk	27
441	tarbaby.junkemailfilter.com	27
442	mgf.cybermail.jp	27
443	mx4.34sp.com	27
444	fimad.interieur.gouv.fr	27
445	mxpool.hostedoffice.ag	27
446	mail.voxops.net	27
447	mx1.onlinemail.io	27
448	mx2.onlinemail.io	27
449	mx2.mailhop.org	27
450	ign-mx1.webglobe.com	27
451	ign-mx2.webglobe.com	27
452	mx1.paypalcorp.com	27
453	mx2.dandomain.dk	27
454	mx0162.ppsmtp.com	27
455	mx0162.ppsmtp.de	27
456	mx-cache.online.net	26
457	mx2.krystal.co.uk	26
458	mail.mailnode.cc	26
459	mx01.espmailservice.net	26
460	bounce.argewebhosting.nl	26
461	eagle-relay.mxlogin.com	26
462	mx1.heinlein-support.de	26
463	mx2.heinlein-support.de	26
464	smtp1.lerelaisinternet.com	26
465	smtp2.lerelaisinternet.com	26
466	mxus1.alibaba-inc.com	26
467	inbound.mail.naiadsystems.com	26
468	mx-ha.emailemnuvem.com.br	26
469	mx01.mi.com.co	26
470	mx1.trustytapir.com	26
471	cloudscan24.ilger.com	26
472	mailgw3.oneoffice.jp	26
473	mail.svethostingu.cz	26
474	mx2.paypalcorp.com	26
475	mx2.spamfiltering.com	26
476	cr1.cylex.de	26
477	serwer1429664.home.pl	26
478	apache.mk.ru	26
479	smx2.web-hosting.com	25
480	mail-s30.1gb.ru	25
481	us1.workspace.org	25
482	sns.nethost.sk	25
483	mg.cybermail.jp	25
484	smtp1-inki.e-i.net	25
485	smtp1-insi.e-i.net	25
486	mx6.eganet.go.tz	25
487	mx.turktelekomeposta.com	25
488	mgp.cybermail.jp	25
489	mx01.rto.de	25
490	mxs.tbank.ru	25
491	mx03.puc.rediris.es	25
492	mx04.puc.rediris.es	25
493	ign-mx3.webglobe.com	25
494	ign-mx4.webglobe.com	25
495	mx1.motosnap.com	25
496	mx2.motosnap.com	25
497	mx1.spamfiltering.com	25
498	mx.shopmania.net	25
499	gateway.aos.rw	25
500	mx001.fatsecret.com	25
501	smx3.web-hosting.com	24
502	mx.viettelidc.com.vn	24
503	mx1.efwd.spaceship.net	24
504	mx2.efwd.spaceship.net	24
505	mx1.gigahost.dk	24
506	mx2.gigahost.dk	24
507	mx3.gigahost.dk	24
508	mail01.be2.com	24
509	mail.ssonet.nl	24
510	mail2.ssonet.nl	24
511	mx3.heinlein-support.de	24
512	mx-aol.mail.gm0.yahoodns.net	24
513	gw-spam.mailwood.com	24
514	mx1.savana.cz	24
515	mx2.savana.cz	24
516	pmx.megacp.com	24
517	bmx.megacp.com	24
518	smtp.sarenet.es	24
519	fallback.axc.eu	24
520	mxf.eu.mpssec.net	24
521	mxg.eu.mpssec.net	24
522	cloudscan25.ilger.com	24
523	mxbackup.wnpower.com	24
524	smartmail1.fednet.gov.ae	24
525	smartmail2.fednet.gov.ae	24
526	mx-mibc-fr-09.mailinblack.com	24
527	mx4c51.megamailservers.eu	24
528	mx1.jimdo.com	24
529	mx2.jimdo.com	24
530	mail.hostalo.it	24
531	aws-useast1-mail.mars-inc.com	24
532	extern-gateway.innogames.de	24
533	mail.mojehobby.pl	24
534	my-mx.email-protect.gosecure.net	23
535	smtp-in0.prod0.webspace.bz	23
536	smtp-in1.prod0.webspace.bz	23
537	mxfallback.spamfilterserver.com	23
538	smx1.web-hosting.com	23
539	mail.lima-city.de	23
540	aspmx.whoisworks.com	23
541	mx.spamservice.nl	23
542	fallbackmx.spamservice.nl	23
543	lastmx.spamservice.nl	23
544	mx1.mail-scanner.eu	23
545	mgk.cybermail.jp	23
546	mx-1.pobox.com	23
547	mx-2.pobox.com	23
548	mx-3.pobox.com	23
549	mfwd.ebrandservices.com	23
550	mail.forumhome.com	23
551	mx1.stsmail.ro	23
552	mx2.stsmail.ro	23
553	mailscanner01.zoner.fi	23
554	mailscanner02.zoner.fi	23
555	captmx-re20.bizflycloud.vn	23
556	captmx-re30.bizflycloud.vn	23
557	captmx-re40.bizflycloud.vn	23
558	smx.megacp.com	23
559	my.mailbux.com	23
560	allegro.in.tmes.trendmicro.eu	23
561	mx1.smashtic.com	23
562	mx4.eganet.go.tz	23
563	mx1.hostcreators.sk	23
564	mx2.hostcreators.sk	23
565	mail.101domain.com	23
566	mail.wroclaw.sa.gov.pl	23
567	mail2.wroclaw.sa.gov.pl	23
568	mail3.wroclaw.sa.gov.pl	23
569	mail4.wroclaw.sa.gov.pl	23
570	parse.mailjet.com	23
571	smtp1.osuosl.org	23
572	smtp2.osuosl.org	23
573	smtp3.osuosl.org	23
574	smtp4.osuosl.org	23
575	mx1.suremail.cn	23
576	mx2.suremail.cn	23
577	mx3.suremail.cn	23
578	mx4.suremail.cn	23
579	mail.mycylex.de	23
580	mx3.hh.ru	23
581	mx.inbox.eu	22
582	mx1.chengmail.cn	22
583	mx2.chengmail.cn	22
584	mta.hosts.net.nz	22
585	mxbackup1.junkemailfilter.com	22
586	mx1.vevida.com	22
587	mx2.vevida.com	22
588	mx3.vevida.com	22
589	alf1.aspmx.whoisworks.com	22
590	alf2.aspmx.whoisworks.com	22
591	mx2.mail-scanner.eu	22
592	mx1.alastyr.com	22
593	mx.c2.icoremail.net	22
594	rk2.comju.de	22
595	mx2.lite-host.su	22
596	mgc.cybermail.jp	22
597	pmg.guzel.net.tr	22
598	pmg2.guzel.net.tr	22
599	ezsmtp.bizmeka.com	22
600	alt1.mymailcheap.com	22
601	mx1.email-hosting.net.au	22
602	mx2.email-hosting.net.au	22
603	mx3.email-hosting.net.au	22
604	mx4.email-hosting.net.au	22
605	m213-mail.server4u.cz	22
606	mx01.hosting.de	22
607	mx02.hosting.de	22
608	mx03.hosting.de	22
609	mxbackup.hosting.de	22
610	mx1.hostingcorreo.com	22
611	mx2.hostingcorreo.com	22
612	mx3.hostingcorreo.com	22
613	mx4.hostingcorreo.com	22
614	mx.sina.net	22
615	mail-in3.rian.ru	22
616	mail-in4.rian.ru	22
617	mx-in.kommunale.it	22
618	mx20.vwgroup.com	22
619	mx01.goneo.de	22
620	mx02.goneo.de	22
621	mx-mibc-fr-05.mailinblack.com	22
622	offline.iserv.eu	22
623	mx.turkticaret.net	22
624	mx6.hh.ru	22
625	mx.vps1.8com.cz	22
626	mx1.grn.es	22
627	mx2.grn.es	22
628	mx4.vevida.com	21
629	backup-mx.vevida.com	21
630	accor.in.tmes.trendmicro.eu	21
631	mx2.alastyr.com	21
632	mx01a.pp-tp.com	21
633	mx02a.pp-tp.com	21
634	rx1.sparkpostmail.com	21
635	rx2.sparkpostmail.com	21
636	rx3.sparkpostmail.com	21
637	mx.portsit.net	21
638	mx.portsit.se	21
639	mx.portsit.com	21
640	alt2.mymailcheap.com	21
641	dmeas11.imail.scig.gov.hk	21
642	dmeas12.imail.scig.gov.hk	21
643	pmeas11.imail.scig.gov.hk	21
644	pmeas12.imail.scig.gov.hk	21
645	blackhole.aftermarket.pl	21
646	mailstream-australia-primary.area1.cloudflare.net	21
647	s2vg300mr01.pzd-svn.de	21
648	s2vg300mr02.pzd-svn.de	21
649	mx01.govmail.gov.jo	21
650	mx02.govmail.gov.jo	21
651	in.widestore.net	21
652	mail.anonaddy.me	21
653	mx1.mailhop.us	21
654	pochta.mtw.ru	21
655	cm2.99sync.com	21
656	smtp.egcloud.gov.eg	21
657	mail.net4india.com	21
658	mxprimary.spamfilterserver.com	21
659	ge-smtp01.gammae.com	21
660	sv62.ifastnet11.org	20
661	mx-a.secumail.de	20
662	mx-b.secumail.de	20
663	mx10.omc.net	20
664	mx01b.pp-tp.com	20
665	mx02b.pp-tp.com	20
666	mx1.mijn.host	20
667	mx2.mijn.host	20
668	mx1.de.opalstack.com	20
669	mx2.de.opalstack.com	20
670	gwmail.ktbizoffice.com	20
671	mx1.greenhost.nl	20
672	mx2.greenhost.nl	20
673	mx4.funlife.cz	20
674	b1234.mx.srv.dfn.de	20
675	c1234.mx.srv.dfn.de	20
676	mail01.phoenixgroup.eu	20
677	mail02.phoenixgroup.eu	20
678	mail03.phoenixgroup.eu	20
679	mail04.phoenixgroup.eu	20
680	mx-in03b.natrohost.com	20
681	mx3.mailinghosting.com	20
682	mx1.em.dingtalk.com	20
683	mx2.em.dingtalk.com	20
684	mail.mbcore.io	20
685	mail.mosby.com	20
686	mx1.secure.ly	20
687	mailgw2.spd.co.il	20
688	mx1.monarobase.net	20
689	mx2.monarobase.net	20
690	mail.system.digitalartscloud.com	20
691	mxc.meoempresas.pt	20
692	mxp.meoempresas.pt	20
693	mail2.anonaddy.me	20
694	mxbackup1.svrsh.com	20
695	mx1.spatiul.ro	20
696	mx2.spatiul.ro	20
697	mx3.spatiul.ro	20
698	mx4.spatiul.ro	20
699	fortispam.cedia.org.ec	20
700	emix.sdv.fr	20
701	ag1.cesnet.cz	20
702	ag2.cesnet.cz	20
703	mx-in04.natrohost.com	20
704	mx-in04b.natrohost.com	20
705	postrelay1.lrz.de	20
706	postrelay2.lrz.de	20
707	filter.premiumantispam.nl	20
708	fallback.premiumantispam.nl	20
709	mx1.belwue.de	20
710	mx.hitcluster.com	20
711	mail.tehila.gov.il	20
712	mx-mibc-fr-03.mailinblack.com	20
713	mx01.earthlink-vadesecure.net	20
714	mx02.earthlink-vadesecure.net	20
715	mx03.earthlink-vadesecure.net	20
716	mx04.earthlink-vadesecure.net	20
717	smtp.sparkpostmail.com	20
718	mail.framasoft.org	20
719	mail.advameg.com	20
720	spam.seoul.go.kr	20
721	spam2.seoul.go.kr	20
722	mx3.eganet.go.tz	20
723	mx.eivoittoa.fi	20
724	mx.vk.com	20
725	mx.spamorez.ru	19
726	antispam04.pensomail.com.br	19
727	mx11.omcnet.de	19
728	mx.skok.cz	19
729	mxbackup.skok.cz	19
730	mail2.greennet.org.uk	19
731	mail.academiadasapostas.com	19
732	a1234.mx.srv.dfn.de	19
733	hzmx02.xmail.ntesmail.com	19
734	reply.s50.exacttarget.com	19
735	mx-in03.natrohost.com	19
736	mx1.a1.net	19
737	ch-mail-fx-001.funix.nl	19
738	of-mail-fx-001.funix.nl	19
739	mx3.em.dingtalk.com	19
740	smtp.tmgrup.com.tr	19
741	avas.cloudemail.be	19
742	mail1.rit.ee	19
743	mail3.rit.ee	19
744	mailstream-syd.area1.cloudflare.net	19
745	mail.cco.in.ua	19
746	mx.fusemail.net	19
747	mxbackup2.svrsh.com	19
748	mx1.mailhop.co	19
749	mx1.mailhop.co.uk	19
750	mxh.eu.mpssec.net	19
751	mxi.eu.mpssec.net	19
752	m103.server4u.cz	19
753	mx.usa.net	19
754	lobo.mercurio.cl	19
755	mx20.profesionalhosting.com	19
756	mx1.niagahoster.co.id	19
757	mx2.niagahoster.co.id	19
758	friday.mxlogin.com	19
759	mx1.promail.com.tr	19
760	mx2.promail.com.tr	19
761	pop2.ocnk.net	19
762	mx01.windstream.net	19
763	mx2.freeola.com	19
764	mx3.freeola.com	19
765	mx4.freeola.com	19
766	mx5.freeola.com	19
767	rcmx3.roscongress.org	19
768	mailfilter.hibox.biz	19
769	mtab.intel.com	19
770	mx.kpnmail.nl	18
771	mxbackup2.junkemailfilter.com	18
772	webmail.mail.maxns.net	18
773	mx1.nethely.hu	18
774	mx2.nethely.hu	18
775	mx-4.pobox.com	18
776	mx-5.pobox.com	18
777	mail.sidecloud.cc	18
778	mx11-new.vatican.va	18
779	mx12-new.vatican.va	18
780	mx20.vatican.va	18
781	mx21.vatican.va	18
782	hzmx01.xmail.ntesmail.com	18
783	mgw.gov.kz	18
784	mx.noip.com	18
785	fm.telconet.net	18
786	mailf.comsats.net.pk	18
787	mx3.daouoffice.com	18
788	mail1.qlc.co.in	18
789	mail2.qlc.co.in	18
790	mail3.qlc.co.in	18
791	avas-backup.cloudemail.be	18
792	mx2.secure.ly	18
793	mx3.secure.ly	18
794	mx4.secure.ly	18
795	mx-in02.natrohost.com	18
796	mx-in02b.natrohost.com	18
797	reply.s13.exacttarget.com	18
798	mailin-01.mx.sonic.net	18
799	mailin-02.mx.sonic.net	18
800	mdn.corp-email.cn	18
801	vip-mail.superhosting.cz	18
802	mx1.antispam-post.ru	18
803	mx2.tmdhosting.com	18
804	rat-01.safaricombusiness.co.ke	18
805	inbound.registeredsite.com	18
806	mxacloud02.imatrix.co.jp	18
807	mail.schroederdennis.de	18
808	mx-in-hfd.apple.com	18
809	mx-in-vib.apple.com	18
810	mx0.mailinblack.com	18
811	mx-in1.euronic.fi	18
812	mx-in2.euronic.fi	18
813	mx3.netregistry.net	18
814	mx2.netregistry.net	18
815	mx.xmission.com	18
816	mx1.reg365.net	18
817	mx2.reg365.net	18
818	mx.ukrdomen.com	18
819	mx2.uh.com.ua	18
820	mail.reed.jp	18
821	mx1.megamailservers.com	18
822	mx01.ofis.net	18
823	mx10.profesionalhosting.com	18
824	mx3.deem.sa	18
825	mx4.deem.sa	18
826	mail-relay-1.nethost.cz	18
827	mx1.progreso.pl	18
828	mx2.progreso.pl	18
829	mx3.progreso.pl	18
830	mx02.mail.alibaba.com	18
831	mx4.belwue.de	18
832	mailgw.mts.rs	18
833	mailforward.iomart.com	18
834	mail2.p24.hu	18
835	mx0.lcn.com	18
836	mx1.lcn.com	18
837	mta.1stdomains.net.nz	18
838	mta5.am0.yahoodns.net	18
839	mta6.am0.yahoodns.net	18
840	mta7.am0.yahoodns.net	18
841	mx.dka.mailcore.net	18
842	mx.ilait.se	18
843	mail03.gov.cy	18
844	mail.lottery.ltd.uk	18
845	selmx5.roscongress.org	18
846	mx-in-1.webreus.nl	17
847	mx-in-2.webreus.nl	17
848	mx1.ex.360.cn	17
849	mx1.sparkspace.huaweicloud.com	17
850	mx2.sparkspace.huaweicloud.com	17
851	ksmg01.picompany.ru	17
852	ksmg02.picompany.ru	17
853	mx01.263xmail.com	17
854	mx1.redhat.com	17
855	mx76.antispam-post.ru	17
856	forwarder.moddies.be	17
857	smtp-gate.gn.apc.org	17
858	mailin2.mx.speedkom.net	17
859	mailin5.mx.speedkom.net	17
860	mx.inbound.elasticemail.com	17
861	mx.bpn.ge	17
862	mr.pavietnam.vn	17
863	mx1.zoner.fi	17
864	mx2.zoner.fi	17
865	mdn.corpemail.net	17
866	mail.cleanmail.eu	17
867	mx.yourpaysitepartner.com	17
868	mxs.hoster.ru	17
869	mx1.tmdhosting.com	17
870	reply.s10.exacttarget.com	17
871	rat-02.safaricombusiness.co.ke	17
872	mx.nameweb.biz	17
873	mercure.credit-agricole.fr	17
874	mail18.lh.pl	17
875	mx.c1.icoremail.net	17
876	mx-in.g.apple.com	17
877	mx-in-mdn.apple.com	17
878	mailgw.mizbanfalocal.com	17
879	smtp1.speednames.com	17
880	smtp1.egcloud.gov.eg	17
881	mx22.gmoserver.jp	17
882	mx3.volusion.com	17
883	mx4.volusion.com	17
884	mx.kpnqwest.it	17
885	mx2.kpnqwest.it	17
886	mx2.megamailservers.com	17
887	mx3.megamailservers.com	17
888	mx01.servicehoster.ch	17
889	mx02.servicehoster.ch	17
890	mx02.ofis.net	17
891	mailmx0001.rlp.de	17
892	mailmx0002.rlp.de	17
893	mail-de.maxcluster.net	17
894	smtp2.speednames.com	17
895	mx.junkemailfilter.net	17
896	mx.junkemailfilter.org	17
897	relay.mail.sec-provider.de	17
898	mail.amamultimedia.com	17
899	mx2.deem.sa	17
900	mx1.deem.sa	17
901	friday-relay.mxlogin.com	17
902	mx01.mail.alibaba.com	17
903	mx2.belwue.de	17
904	mx3.belwue.de	17
905	mail.mymail.eu.com	17
906	bmx01.neodigit.net	17
907	bmx02.neodigit.net	17
908	mgy.cybermail.jp	17
909	inbound-reply.s1.exacttarget.com	17
910	antispamawn.thaicloudsolutions.com	17
911	newsletter.cylex.de	17
912	mx1.bionicmoose.com	17
913	mx-in1001.wikimedia.org	17
914	mx-in2001.wikimedia.org	17
915	dns10977.phdns5.es	17
916	mx1.spamorez.ru	16
917	mx.latnet.lv	16
918	mx2.latnet.lv	16
919	mx1.mschosting.com	16
920	mx2.mschosting.com	16
921	mxc.ptempresas.pt	16
922	mx32.antispam-post.ru	16
923	mail-in.protection.bpce-it.fr	16
924	eu1.workspace.org	16
925	us4-smtp-mx1.titanhq.com	16
926	us4-smtp-mx2.titanhq.com	16
927	mailx.hoster.ru	16
928	mx01mi.neen.it	16
929	mx02mi.neen.it	16
930	alt1.cloudcone.mx	16
931	alt2.cloudcone.mx	16
932	mx01.logixmx.com	16
933	mx02.logixmx.com	16
934	mx.mijnspamfilter.nl	16
935	mx1.cloudaccess.net	16
936	mx2.cloudaccess.net	16
937	mail2.motorpresse.de	16
938	mx21.gmoserver.jp	16
939	mx2.bgdns.net	16
940	secmail.iap.socgen.com	16
941	lae-mx2.daybreakgames.com	16
942	spamwall.redwarning.com	16
943	fallback1.server.eu	16
944	fallback2.server.eu	16
945	mia1-load.supramail.com.br	16
946	mx03.mi.com.co	16
947	maila.dubai.gov.ae	16
948	mailb.dubai.gov.ae	16
949	mailc.dubai.gov.ae	16
950	mx.inet.vn	16
951	mx0.spamfilter.gr	16
952	mx1.spamfilter.gr	16
953	mx-in-rno.apple.com	16
954	mx1.mailhop.org	16
955	smtp01.wmaker.net	16
956	smtp02.wmaker.net	16
957	mxbjm.chinaemail.cn	16
958	ns10.sansung.net	16
959	mail2.bytecamp.net	16
960	mail.casinocontroller.com	16
961	mxbackup01.ofis.net	16
962	mx1.flockmail.com	16
963	mx2.flockmail.com	16
964	mail.fpack.jp	16
965	ofcsgbbm.gbbmvi-wan.de	16
966	zbcsgbbm.gbbmvi-wan.de	16
967	mx.junkemailfilter.com	16
968	mail-cc.maxcluster.net	16
969	mx02.dioezesennetz.de	16
970	mx01.dioezesennetz.de	16
971	dhl-com.fortimailcloud.com	16
972	backup.mail.profiwh.com	16
973	m4.xrea.com	16
974	mailscanner.powerhosting.dk	16
975	mail.tubecj.com	16
976	mail2535230.us.to	16
977	ksmg.mail.rwb.ru	16
978	uk1-smtp-mx1.titanhq.com	16
979	uk1-smtp-mx2.titanhq.com	16
980	mail.atw.hu	16
981	mail2.atw.hu	16
982	rtmx2.roscongress.org	16
983	a.mx.tojeono.cz	16
984	mail.myonlineradio.hu	16
985	mx-ws.dca.untd.com	15
986	mx-ws.vgs.untd.com	15
987	mail.bizboxa.com	15
988	smtp1.mafra.cz	15
989	smtp2.mafra.cz	15
990	smtp3.mafra.cz	15
991	smtp4.mafra.cz	15
992	smtp.webnames.ca	15
993	mx1.nine.ch	15
994	mx2.nine.ch	15
995	mail.messaging.microsoft.com	15
996	mail.endora.cz	15
997	spamschutz.webhoster.de	15
998	mfwd.eurodns.com	15
999	mail.mmmmmmmm.pw	15
1000	mail1.bravehost.com	15

100 curiosities — singleton hostnames

Hostnames that appear exactly once in the Tranco top-1M (count == 1), sorted by length descending. These are the most bespoke / unusual setups — long custom names, region-specific hosters, one-off corporate gateways. Useful for qualitative research.

#	MX target (rare singleton)
1	nomcom-postfixnlb-primary-prd-9b67717506e5a5b8.elb.ap-northeast-1.amazonaws.com
2	a054cd5b956464acb8abb27a3c6bdd9a-85ac2eeef24e1085.elb.us-east-1.amazonaws.com
3	port-arthur-historic-site-management-authority-mx1.firstcloudsecurity.net
4	port-arthur-historic-site-management-authority-mx2.firstcloudsecurity.net
5	cubic-transportation-systems-australia-mx1.firstcloudsecurity.net
6	cubic-transportation-systems-australia-mx2.firstcloudsecurity.net
7	kumomta-inbound-nlb-a0dcfe14e184840a.elb.us-east-2.amazonaws.com
8	realf-applb-vrxtwmiuyvuv-2103991361.us-west-1.elb.amazonaws.com
9	c376242079468b63f23f69becab45ae05b58a20e3873f77f83b2288f3647007
10	manak-waste-management-private-ltd-mx1.firstcloudsecurity.net
11	manak-waste-management-private-ltd-mx2.firstcloudsecurity.net
12	remai-art-gallery-of-saskatchewan-mx1.firstcloudsecurity.net
13	55mth-mail-26b47d887ec242c7.elb.ap-northeast-1.amazonaws.com
14	remai-art-gallery-of-saskatchewan-mx2.firstcloudsecurity.net
15	p3plzcpnl502916.prod.phx3.secureserver.net.eco-reglalos.com
16	emailserver-2e1b0065310ca62b.elb.ca-central-1.amazonaws.com
17	scprd2-p1-aadd52a9a99424fb.elb.ap-northeast-1.amazonaws.com
18	df-nu4a-g8rhv-jl689-g9c89-ruukm-t7dhr.in.tmes.trendmicro.eu
19	mx1.123-regmmailsec.protonmail.chailsec.protonmail.ch.co.uk
20	8ad2f72d-b2c4-4426-93fd-baacf7213b2d.in.tmes.trendmicro.eu
21	_dc-mx.fc2dea773184.medicalteaching.org.cdn.cloudflare.net
22	manulifesinochem-com02b.mail.protection.partner.outlook.cn
23	knowbe4-site-verification=34b9a58212e47bbcdf835890f6facdda
24	europeanchamber-com-cn.mail.protection.partner.outlook.cn
25	printondemand-worldwide.com.pri-mx.uk0101.smtproutes.com

Show rows 26 – 100

#	MX target (rare singleton)
26	lb-sensproxy-2213375-dc68d533ade4.kr-gov.lb.naverncp.com
27	audifawnev-com-cn01bb.mail.protection.partner.outlook.cn
28	neusoftmedical-com01i.mail.protection.partner.outlook.cn
29	canaancreative-com01e.mail.protection.partner.outlook.cn
30	nfi34bdspmurbud57axm3w3xj2oyegddbnn6576ooea2jqnvu2mq.mx-
31	etpr3nvk46n27vcc4juimkc7lxqosohb2zurr75mhylme5ye3awa.mx
32	nospamcloudserver.germanywestcentral.cloudapp.azure.com
33	ec2-54-250-119-230.ap-northeast-1.compute.amazonaws.com
34	u003d1a3b487390464833982a65fae59682b8.pamx1.hotmail.com
35	porschepreview-cn01i.mail.protection.partner.outlook.cn
36	ipolaristech-com02b.mail.protection.partner.outlook.cn
37	ec2-54-249-67-111.ap-northeast-1.compute.amazonaws.com
38	zhengduindustry-com.mail.protection.partner.outlook.cn
39	ec2-54-249-80-136.ap-northeast-1.compute.amazonaws.com
40	ec2-54-249-53-219.ap-northeast-1.compute.amazonaws.com
41	638d21520d5d8632ca41f2350704980f00eee5ee.msv1.invalid
42	279c75a743b1712505623de1926da99446f03967.msv1.invalid
43	dd65647d11fb1053fa50107650b42fc91a436e09.msv1.invalid
44	b9b6ae914169a5a1688b1ae10978544884baaeb2.msv1.invalid
45	398fee270f77f506c1cc48e3a278690a231969e0.msv1.invalid
46	voipdnsservers-com.mail.protection.outlook.comook.com
47	d8ef932105e6cdcd8d95d568e0ceb61e012b76b4.msv1.invalid
48	c7d3d7276f30dc72efbeb8e54423b1b47f63c58c.msv1.invalid
49	e57689ebf1cee2dcc74ca9695ba1a35f5249a903.msv1.invalid
50	st-leonards-medical-clinic-mx2.firstcloudsecurity.net
51	f78862464ed0b6cbe472a0576b0fbb2ac6d05878.msv1.invalid
52	0fcc78af48b44f7236938cb34abbc42e37e614bf.msv1.invalid
53	e1373a12bca10839245327b9929bbbb41f14a8b3.msv1.invalid
54	c37b41cc2aa83c50b8571a4fc41db855c664ecb8.msv1.invalid
55	4b21ca12bd08ff22911a3537cf16967c602f815c.msv1.invalid
56	b0ffb392998bbac22514f47efc669d776443e592.msv1.invalid
57	7a1b696a13d31b9dd635db9c58d1f1c23c2c8288.msv1.invalid
58	90567ad2edb4ac9680d76a5d4492522415dc356e.msv1.invalid
59	a65de67cec3cffe17a5ac1f81aa42b22b2bcc8bb.msv1.invalid
60	5630e8ec42dcf18d9f086f6c16eb2667db34ace6.msv1.invalid
61	7544859033090d52a1be915fe96b1ec34f4dfd58.msv1.invalid
62	st-leonards-medical-clinic-mx1.firstcloudsecurity.net
63	7d647202e4a762b842051e7ec60ff2fbd7fa2867.msv1.invalid
64	mercedesbenz-cn02b.mail.protection.partner.outlook.cn
65	f59062e299f55da9447ced93e0ca43a2524e3386.msv1.invalid
66	0e52eafae7d1afa59efc92fe1a4ff3276f8eed08.msv1.invalid
67	d3289eaaa594de2bf98e995630fdf76eb646bd67.msv1.invalid
68	8fca991f22bf0d3d9888adf9a9f177956ff29643.msv1.invalid
69	be7c5e09a4d9047e88c98c8bdd5c0306855692b8.msv1.invalid
70	8128664d7b9f7560c069c1bc8e6e2288e53721dc.msv1.invalid
71	explorationpub-com.mail.protection.partner.outlook.cn
72	printondemand-worldwide.com.bak-mx.uk0101.smtpbak.com
73	86da5df266ee85ba1c9b2e19f890526f1191355e.msv1.invalid
74	52f27914d6785f1569d999124b030c5d757f88dc.msv1.invalid
75	mailserver-elb-2061444691.us-east-1.elb.amazonaws.com
76	261fab891c9e30b9a8437b2307e7e67ebbfeee85.msv1.invalid
77	b7d2174f2e1b3ef1065ffa8a05f24e3ca87487e4.msv1.invalid
78	51e1151fac65ad93d2c3cb907f9a1e1bb5976586.msv1.invalid
79	b894a10f9d664f0b272df24349d0136fba05a89b.msv1.invalid
80	23a61b54849a99e548624c09d1cdddef7ffb2764.msv1.invalid
81	7312c3dbeed587e1ca48d18b0132c7c7d3d449d0.msv1.invalid
82	\234\176\149\235\130\168\235\167\155\236\167\145.net
83	qctzdy9yn1z9q3cj.gpqh6jl7d4xobee0.pki-validation.com
84	f32ulet7jexwiwmrwipot2hs332uejyx5q5nwf3ggp77wer7utca
85	3aas5bdlzoabws5g7mber6wtuyuvqjldemho2xwpx2pjf36yejoa
86	mfbwxutmypci.mail-manager-smtp.ap-southeast-2.on.aws
87	t2hbn3v62hu8w3s5.nx7lu0xvfrcp3ikg.pki-validation.com
88	gdsservices-com0i.mail.protection.partner.outlook.cn
89	jqtyfzs58md1ra71.dbb7owi5iazdyuvq.pki-validation.com
90	ec2-54-249-8-39.ap-northeast-1.compute.amazonaws.com
91	5c7am4rrhs7xh7sgmu74qjaqd4phx2qifzbv6jl3i3xz3zhjqqqq
92	outdoormaster-com.mail.protection.partner.outlook.cn
93	3osdx5cysr5ezqynjk3rxbwfxkoqwt47ek32cdcy7uar65mfindq
94	porschepcn-com01i.mail.protection.partner.outlook.cn
95	decathlon-com-cn.mail.protection.partner.outlook.cn
96	healthkeepers-cn.mail.protection.partner.outlook.cn
97	chevrolet-com-cn.mail.protection.partner.outlook.cn
98	hamamatsu-com-cn.mail.protection.partner.outlook.cn
99	switchbot-com01e.mail.protection.partner.outlook.cn
100	baishancloud-com.mail.protection.partner.outlook.cn

TLD breakdown of Unknown bucket

Where the unmatched domains live, by registry suffix. Two-level TLDs like co.uk and com.br are recognised.

#	TLD	Domains in Unknown bucket
1	com	22 661
2	de	5 341
3	net	4 504
4	ru	3 378
5	org	2 743
6	pl	1 948
7	jp	1 559
8	it	1 490
9	fr	1 433
10	cz	1 328
11	co.uk	1 204
12	nl	1 137
13	cfd	1 012
14	com.br	877
15	eu	832

Methodology in 30 seconds

Source: daily OpenINTEL Tranco snapshot (forward DNS, top-1M).
"Unknown / Generic": domains whose primary MX hostname does not match any entry in dictionaries/mx_providers.py (named providers) or generic mail.* / mx*.* patterns we attribute to "Generic / Self-hosted".
Self-hosted: the primary MX equals the apex domain or is a subdomain of it (example.com → mx.example.com).
Curiosities: hostnames with exactly one observation in the snapshot, sorted by length descending. Deterministic — same snapshot ⇒ same list.
Reproducibility: all CSVs are downloadable verbatim. No proprietary enrichment.

Generated automatically from OpenINTEL Tranco snapshot 2026-09-10. Aggregates only — raw data is deleted after analysis per the OpenINTEL data agreement.