Long-tail of email infrastructure — 2026-05-04

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

At a glance

Unknown / Generic12.39%82 133 domainsUnique unmatched MX37 149individual hostnamesSelf-hosted23.06%152 855 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	nan	4 443
2	localhost	338
3	mx-biz.mail.am0.yahoodns.net	308
4	asapsemi1.mail.protection.office365.us	300
5	mail	276
6	mx.services	253
7	mx01.1and1.com	186
8	~	185
9	mx00.1and1.com	180
10	mail.autoline.com.ua	176
11	mx2.z-ns.net	174
12	mail1.sbnation.com	172
13	zonemx.eu	171
14	mx.email-messaging.com	140
15	alltheemails.com	130
16	mx1.emailsendhub.com	121
17	uk.mx1.mailanyone.net	119
18	uk.mx2.mx25.net	119
19	relay1.netnames.net	118
20	relay2.netnames.net	118
21	uk.mx3.mailanyone.net	117
22	mxi.alpha-prm.jp	116
23	s.mail.dcsaas.net	116
24	mx240.umbler.co.uk	113
25	se.mx1.mailanyone.net	113
26	se.mx2.mx25.net	113
27	mx.simply.com	112
28	mx364.umbler.com	112
29	uk.mx4.mx25.net	112
30	offline.iserv.eu	112
31	mx1.ticketsinbound.com	111
32	mx2.ticketsinbound.com	109
33	se.mx3.mailanyone.net	108
34	se.mx4.mx25.net	107
35	mwpremgw1.ocn.ad.jp	105
36	mx1d10.thinline.cz	104
37	mwpremgw2.ocn.ad.jp	104
38	mx00.1and1.co.uk	103
39	mx1b20.thinline.cz	103
40	mx10.websupport.sk	103
41	mx20.websupport.sk	103
42	cloudmail.auto-vision.ru	102
43	mailin.mx-hub.cz	101
44	mailin.mx-hub.sk	101
45	mx01.1and1.co.uk	100
46	mx1.cleanmx.pt	100
47	mx01.lancloud.ru	100
48	mx02.lancloud.ru	100
49	mx04.lancloud.ru	100
50	mx2.cleanmx.pt	99

Show rows 51 – 1000

#	MX target	Domains
51	mx03.lancloud.ru	98
52	mailin.mx-hub.eu	97
53	mx01.mailplug.com	96
54	void.blackhole.mx	95
55	mx02.mailplug.com	95
56	mx.zoho.com.au	91
57	mx2.zoho.com.au	91
58	mx3.zoho.com.au	90
59	mx.zoho.com.cn	88
60	mx2.zoho.com.cn	87
61	mx.hetemail.jp	87
62	amazon-smtp.amazon.com	87
63	mailforward.dnsv.jp	84
64	mx4.name.com	83
65	mx3.name.com	83
66	smtp-fwd.wordpress.com	83
67	mx-backup.serveriai.lt	83
68	mx6.name.com	82
69	mx5.name.com	82
70	mx8.name.com	82
71	mx7.name.com	81
72	mx-proxy501.heteml.jp	81
73	mx1.atmosphere.facct.ru	80
74	mail.global.frontbridge.com	80
75	mx1.email-cluster.com	80
76	mx2.email-cluster.com	80
77	mx-proxy502.heteml.jp	79
78	mx2.atmosphere.facct.ru	79
79	antispam1.ihs.com.tr	78
80	antispam2.ihs.com.tr	78
81	mx.aams4.jp	77
82	failover1.email-cluster.com	77
83	mx.maxns.net	76
84	mxint01.1and1.com	75
85	mxint02.1and1.com	75
86	mx-0.aams4.jp	74
87	mx-1.aams4.jp	74
88	mx-01.mail-forwarder.io	74
89	mx6.kvnbw.de	74
90	mx7.kvnbw.de	74
91	mx8.kvnbw.de	74
92	mx9.kvnbw.de	74
93	sitemail.everyone.net	73
94	mx.vshosting.eu	73
95	posta.mediacenter.hu	72
96	posta2.mediacenter.hu	72
97	posta4.mediacenter.hu	72
98	posta5.mediacenter.hu	72
99	smtp.faisco.cn	72
100	mx1-dk.centerasecurity.dk	71
101	mx2-dk.centerasecurity.dk	71
102	posta3.mediacenter.hu	71
103	mx01.1and1.es	71
104	mx-02.mail-forwarder.io	71
105	q01es.mail.s-web.de	70
106	q02es.mail.s-web.de	70
107	r01es.mail.s-web.de	70
108	r02es.mail.s-web.de	70
109	gmail22.gadmail.de	69
110	gmail23.gadmail.de	69
111	wmail22.gadmail.de	69
112	smtp-avas.seeweb.it	68
113	wmail23.gadmail.de	68
114	mx.sendcloud.org	67
115	mx00.1and1.fr	67
116	mx01.1and1.fr	67
117	mx00.1and1.es	67
118	mx1.netim.net	66
119	mx2.netim.net	66
120	mail-fr.securemail.pro	66
121	mx4.emailowl.com	65
122	mx3-dk.centerasecurity.dk	65
123	mxa.expediagroup.com	64
124	mxb.expediagroup.com	64
125	mx.emailarray.com	64
126	mx2.emailarray.com	64
127	rmail22.gadmail.de	64
128	rmail23.gadmail.de	64
129	mx5.emailowl.com	63
130	usa.mx1.mailanyone.net	63
131	omail22.gadmail.de	63
132	omail23.gadmail.de	63
133	mx6.emailowl.com	62
134	usa.mx3.mailanyone.net	62
135	mx1.daouoffice.com	62
136	usa.mx2.mx25.net	60
137	usa.mx4.mx25.net	60
138	mx.spamfilter.io	59
139	email.webglobe.cz	59
140	email2.webglobe.cz	59
141	d01es.mail.s-web.de	59
142	d02es.mail.s-web.de	59
143	e01es.mail.s-web.de	59
144	e02es.mail.s-web.de	59
145	spamexpert01.host.bg	58
146	spamexpert02.host.bg	58
147	mail.mpcloud.net	57
148	mail.pickelhost.com	57
149	generalsmtp.disney.com	57
150	email3.webglobe.cz	57
151	email4.webglobe.cz	57
152	heracles.mxrouting.net	57
153	mx2.daouoffice.com	57
154	mx.mymailwall.com	57
155	webmail.terrawan.eu	57
156	mail2.no-ip.com	56
157	mx01.muumuu-mail.com	56
158	heracles-relay.mxrouting.net	55
159	mx01.statens-it.dk	55
160	mx02.statens-it.dk	55
161	mx03.statens-it.dk	55
162	mx04.statens-it.dk	55
163	mx05.statens-it.dk	55
164	mx06.statens-it.dk	55
165	mx07.statens-it.dk	55
166	mx08.statens-it.dk	55
167	mx1.simplelogin.co	54
168	mx2.simplelogin.co	54
169	antispam.tebilisim.com	54
170	mail-in.fruugo.net	54
171	mta.vshosting.eu	53
172	mail1.no-ip.com	53
173	antispam.korea.kr	53
174	mx01.cbsolt.net	52
175	mx02.cbsolt.net	52
176	mx4.nameshield.net	52
177	dk.mx1.mailanyone.net	52
178	dk.mx2.mx25.net	52
179	mx2.smtp.goog	52
180	mx3.smtp.goog	52
181	mx4.smtp.goog	52
182	mx1.netsolmail.net	52
183	mail.bayern.de	52
184	mx1.oderland.com	51
185	mx2.oderland.com	51
186	dk.mx3.mailanyone.net	51
187	mx1.smtp.goog	51
188	adresseavisen.in.tmes.trendmicro.eu	51
189	mx-mibc-fr-11.mailinblack.com	51
190	mx01.glesys.se	51
191	mail.idp365.net	51
192	mx1.nepal.gov.np	51
193	mx1.alwaysdata.com	50
194	mx2.alwaysdata.com	50
195	mx2.nepal.gov.np	50
196	g01es.mail.s-web.de	50
197	g02es.mail.s-web.de	50
198	mars.intermailgate.com	50
199	y01es.mail.s-web.de	49
200	y02es.mail.s-web.de	49
201	wednesday.mxrouting.net	49
202	dk.mx4.mx25.net	49
203	mx-n.global-mail.cn	49
204	mail.bluetie.com	48
205	wednesday-relay.mxrouting.net	48
206	mx02.glesys.se	48
207	mx3.oderland.com	47
208	mx4.oderland.com	47
209	mailgw01.host.it	47
210	mx1.webhouse.sk	47
211	mx2.webhouse.sk	47
212	mx3.webhouse.sk	47
213	mx-1.mail.go.id	47
214	mx-2.mail.go.id	47
215	mx-3.mail.go.id	47
216	mx-4.mail.go.id	47
217	mg.g-cloud.by	47
218	mx01.easyname.eu	47
219	mx02.easyname.eu	47
220	mail.dms.unileverservices.com	47
221	mail.vipmailservice.com	47
222	mail.twincdn.com	47
223	p.webcom.ctmail.com	46
224	mailgw02.host.it	46
225	mxs.ht-systems.ru	46
226	mail02.mail-gw.de	46
227	mail03.mail-gw.de	46
228	mail2.recop.jp	45
229	glacier-relay.mxrouting.net	45
230	mx.otenet.gr	45
231	mx1.bund.de	45
232	glacier.mxrouting.net	44
233	mail.univalence.com	44
234	mxpool.de2.hostedoffice.ag	44
235	mx2.otenet.gr	44
236	mx2.bund.de	44
237	mx3.hh.ru	44
238	ni-spamexperts.guzel.net.tr	43
239	mail.valtori.fi	43
240	mx1.pokingbear.com	43
241	mx6.hh.ru	43
242	eu-esec-01.heimdalsecurity.com	42
243	eu-esec-02.heimdalsecurity.com	42
244	smtp-in-internet-usr-m.gslb.srv.bnpparibas	42
245	inbound01.dynata.com	42
246	inbound02.dynata.com	42
247	inbound03.dynata.com	42
248	mx3.otenet.gr	42
249	a1.spambusters.email	41
250	n1.spambusters.email	41
251	mx.noris.net	41
252	mail4.makeshop.jp	41
253	mx1.emailowl.com	41
254	mail.gigaserver.cz	41
255	mx1.daringibex.com	41
256	mx1-n.global-mail.cn	41
257	mx4.otenet.gr	41
258	mail2.careerjet.net	41
259	mail1.digikey.com	41
260	mail2.digikey.com	41
261	mail3.digikey.com	41
262	mx1.supremebox.com	40
263	mx2.supremebox.com	40
264	mail.parktons.com	40
265	mail1.correo.gob.es	40
266	mail2.correo.gob.es	40
267	inbound.postmarkapp.com	40
268	mx.getcourse.ru	40
269	mailgw.nic.in	40
270	mx2.emailowl.com	39
271	mx3.emailowl.com	39
272	mx1.mythic-beasts.com	39
273	mx2.mythic-beasts.com	39
274	mx1.daemonmail.net	39
275	mx2.daemonmail.net	39
276	mx1.tmdhosting.com	39
277	mx2.tmdhosting.com	39
278	mx.stable.cz	39
279	mx01.ergonet.it	39
280	mx02.ergonet.it	39
281	mx03.ergonet.it	39
282	mx04.ergonet.it	39
283	mxmail.icoremail.net	39
284	mx2.postmaster.hu	39
285	zc-mx.zohocorp.com	39
286	zc-mx2.zohocorp.com	39
287	zc-mx3.zohocorp.com	39
288	1-grid-mx03.co.za	38
289	blizzard.mxrouting.net	38
290	shadow.mxrouting.net	38
291	mx1.loading.es	38
292	mx2.loading.es	38
293	mx3.loading.es	38
294	mxgw.bcc.gov.bd	38
295	mx01.wirtgen-group.com	38
296	mx02.wirtgen-group.com	38
297	1-grid-mx02.com	37
298	1-grid-mx04.com	37
299	1-grid-mx01.co.za	37
300	mxwcom.263xmail.com	37
301	mail.lima-city.de	37
302	blizzard-relay.mxrouting.net	37
303	mx100.ucozmail.com	37
304	mx1.dnsmadeeasy.com	37
305	mx2.dnsmadeeasy.com	37
306	mx2.mijndomein.nl	37
307	smtp-avas-th.seeweb.it	37
308	tuesday-relay.mxrouting.net	37
309	mail-8.mtpserver.net	37
310	mail-12.mtpserver.net	37
311	mail-13.mtpserver.net	37
312	mxcom.263xmail.com	36
313	mx1.1984.is	36
314	smtp-scan01.mx.reflected.net	36
315	fakemx.noris.net	36
316	mx4.webhouse.sk	36
317	mx5.webhouse.sk	36
318	mx6.webhouse.sk	36
319	mxs.armgs.team	36
320	mx1.mas.t-systems-service.com	36
321	mx3.dnsmadeeasy.com	36
322	assur.rtl.de	36
323	marduk.rtl.de	36
324	sul.rtl.de	36
325	sulis.rtl.de	36
326	securemx01.mailplug.com	36
327	securemx02.mailplug.com	36
328	us1-smtp-mx1.titanhq.com	36
329	mx1.mijndomein.nl	36
330	taylor.mxrouting.net	36
331	mxbackup.wnpower.com	36
332	pri-jeemsg.eemsg.mail.mil	36
333	sec-jeemsg.eemsg.mail.mil	36
334	tuesday.mxrouting.net	36
335	mail.nhs.uk	36
336	mx2.1984.is	35
337	mail.techsurgeons.com	35
338	shadow-relay.mxrouting.net	35
339	mmxs.majordomo.ru	35
340	mx.siteprotect.com	35
341	echo.mxrouting.net	35
342	mail73.conoha.ne.jp	35
343	us1-smtp-mx2.titanhq.com	35
344	mx.stable.sk	35
345	cloudmail01.clausweb.ro	35
346	cloudmail02.clausweb.ro	35
347	cloudmail03.clausweb.ro	35
348	cloudmail04.clausweb.ro	35
349	mx.easymail.ca	35
350	mx.renr.es	35
351	mx2c51.megamailservers.eu	35
352	mail.makeup.com.ua	35
353	mailbox.wargaming.net	35
354	mx.noris.de	34
355	mx2.mas.t-systems-service.com	34
356	mx3.mas.t-systems-service.com	34
357	mx1.nz.smxemail.com	34
358	echo-relay.mxrouting.net	34
359	arrow.mxrouting.net	34
360	mx-dor.bell.ca	34
361	mx-wyn.bell.ca	34
362	mx.cstnet.cn	34
363	wmx.ecounterp.com	33
364	fusion.mxrouting.net	33
365	fusion-relay.mxrouting.net	33
366	mail11.hmail.sg	33
367	mail21.hmail.sg	33
368	mail.postale.io	33
369	securemail-mx1.synaq.com	33
370	mx0.mail7.freehost.com.ua	33
371	mx1.mail7.freehost.com.ua	33
372	mx2.mail7.freehost.com.ua	33
373	mx.buzondecorreo.com	33
374	mforward.dtag.de	33
375	mx1.alibaba-inc.com	33
376	semail.sandhills.com	33
377	wemail.sandhills.com	33
378	mx1.us.opalstack.com	33
379	mx2.us.opalstack.com	33
380	mx.claramail.com.br	33
381	gatekeeper.space.net	33
382	gatekeeper.spacenet.de	33
383	aspmx1.dooray.com	33
384	reply.s12.exacttarget.com	33
385	relay.exohosting.sk	33
386	mx1.tigertech.net	32
387	mx2.tigertech.net	32
388	mx3.tigertech.net	32
389	securemail-mx2.synaq.com	32
390	mail3.makeshop.jp	32
391	mx01.agnat.pl	32
392	france.security-mail.net	32
393	europe.security-mail.net	32
394	mxs.activeby.net	32
395	arrow-relay.mxrouting.net	32
396	mail.joker.com	32
397	smtp.renault.fr	32
398	smtp2.renault.fr	32
399	mx-mibc-fr-06.mailinblack.com	32
400	mx01.routing.net	32
401	mx03.routing.net	32
402	in.widestore.net	32
403	mx.ms.bi.zone	32
404	mail.swisscom.com	32
405	mail10.swisscom.com	32
406	mail20.swisscom.com	32
407	mail-s30.1gb.ru	31
408	pixel.mxrouting.net	31
409	mx2.nz.smxemail.com	31
410	mail.voxops.net	31
411	mx-mibc-fr-07.mailinblack.com	31
412	mx1.trustytapir.com	31
413	mx.serveriai.lt	31
414	mx1.savana.cz	31
415	mx2.savana.cz	31
416	fimad.interieur.gouv.fr	31
417	mx02.routing.net	31
418	mt-spamexperts.guzel.net.tr	31
419	ssl.emailserver.vn	31
420	mxc.global-mail.cn	31
421	mailasp.sovcombank.ru	31
422	mail.cm.telia.net	31
423	mail.dyson.cloud	31
424	mx.x.recruit.co.jp	30
425	mx.fimn.net	30
426	mx-mibc-fr-08.mailinblack.com	30
427	us1.workspace.org	30
428	ntvirus.url.com.tw	30
429	ntvirus2.url.com.tw	30
430	mx-10.au-east.atmailcloud.com	30
431	mx-20.au-east.atmailcloud.com	30
432	mx-waw.grupawp.pl	30
433	mx-gda.grupawp.pl	30
434	inmx.rambler-co.ru	30
435	mx.mailo.com	30
436	mx1.dfw.automattic.com	30
437	taylor-relay.mxrouting.net	30
438	mx2.mailhop.org	30
439	mx10.vwgroup.com	30
440	mail.lakennetwork.com	30
441	mx10.websupport.se	30
442	mail.svethostingu.cz	30
443	mxu.global-mail.cn	30
444	dmeas13.imail.scig.gov.hk	30
445	dmeas14.imail.scig.gov.hk	30
446	pmeas13.imail.scig.gov.hk	30
447	pmeas14.imail.scig.gov.hk	30
448	mg1.g-cloud.by	29
449	eu1-smtp-mx1.titanhq.com	29
450	mx-a.secumail.de	29
451	mx-b.secumail.de	29
452	mx-ha.emailemnuvem.com.br	29
453	mx01.espmailservice.net	29
454	tarbaby.junkemailfilter.com	29
455	eagle.mxlogin.com	29
456	mxin1.airnet.ne.jp	29
457	mxin2.airnet.ne.jp	29
458	cnc.biz-email.net	29
459	mx2.ams.automattic.com	29
460	mxc.ptempresas.pt	29
461	mail.cmposta.com	29
462	cmx.yaanimail.com	29
463	mx.mailbox.orange-business.com	29
464	mailin100.dcpserver.de	29
465	mmx.mail.gov.az	29
466	mx20.websupport.se	29
467	mx1.paypalcorp.com	29
468	smtp.dvtech.io	29
469	mx01.ntc.net.pk	29
470	mx2.pokerstars.com	29
471	mx-mibc-fr-10.mailinblack.com	28
472	smx2.web-hosting.com	28
473	mx1.krystal.io	28
474	mx2.krystal.io	28
475	mx.viettelidc.com.vn	28
476	pixel-relay.mxrouting.net	28
477	mail.sidecloud.cc	28
478	alt1.mymailcheap.com	28
479	mx01.tophost.ch	28
480	mxus1.alibaba-inc.com	28
481	mailgw3.oneoffice.jp	28
482	mail.variomedia.de	28
483	rmx.mailgw.jp	28
484	mx2.paypalcorp.com	28
485	mail-relay.wetteronline.de	28
486	eu1-smtp-mx2.titanhq.com	27
487	mx3.34sp.com	27
488	mx4.34sp.com	27
489	mx1.mailer91.com	27
490	mx2.mailer91.com	27
491	mx1.onlinemail.io	27
492	mx2.onlinemail.io	27
493	witcher.mxrouting.net	27
494	witcher-relay.mxrouting.net	27
495	mailx.hoster.ru	27
496	mx-1.pobox.com	27
497	alt2.mymailcheap.com	27
498	mx1.heinlein-support.de	27
499	mx2.heinlein-support.de	27
500	blackhole.aftermarket.pl	27
501	mail.biz-email.net	27
502	alt2-mx.rackhostmx.com	27
503	mgp.cybermail.jp	27
504	mxp.ptempresas.pt	27
505	mx.online.net	27
506	mxbackup.routing.net	27
507	mx01.rto.de	27
508	mx1.krystal.co.uk	27
509	mxs.tbank.ru	27
510	mx.usa.net	27
511	mx01.earthlink-vadesecure.net	27
512	mx02.earthlink-vadesecure.net	27
513	mx03.earthlink-vadesecure.net	27
514	mx04.earthlink-vadesecure.net	27
515	aws-useast1-mail.mars-inc.com	27
516	relay1.exohosting.sk	27
517	relay3.dnsserver.eu	27
518	mx0162.ppsmtp.com	27
519	mx0162.ppsmtp.de	27
520	corpmx.yelpcorp.com	27
521	smx3.web-hosting.com	26
522	redbull.mxrouting.net	26
523	redbull-relay.mxrouting.net	26
524	mx10.active24.cz	26
525	mx20.active24.cz	26
526	mail01.be2.com	26
527	mx-2.pobox.com	26
528	mx-3.pobox.com	26
529	mx02.tophost.ch	26
530	eagle-relay.mxlogin.com	26
531	mx3.heinlein-support.de	26
532	mx1.stsmail.ro	26
533	mx2.stsmail.ro	26
534	pmx.megacp.com	26
535	bmx.megacp.com	26
536	mx-cache.online.net	26
537	mx2.krystal.co.uk	26
538	mx.turkticaret.net	26
539	mx2.spamfiltering.com	26
540	mx.shopmania.net	26
541	relay2.dnsserver.eu	26
542	smx1.web-hosting.com	25
543	work-mx.app.hey.com	25
544	mx1.mail-scanner.eu	25
545	webmail.mail.maxns.net	25
546	mail1.ethionet.et	25
547	mail2.ethionet.et	25
548	mail3.ethionet.et	25
549	mgc.cybermail.jp	25
550	mx.zohocloud.ca	25
551	ge-smtp01.gammae.com	25
552	smx.megacp.com	25
553	m213-mail.server4u.cz	25
554	allegro.in.tmes.trendmicro.eu	25
555	ezsmtp.bizmeka.com	25
556	mxpool.hostedoffice.ag	25
557	mx01.emailpnl.com	25
558	mx02.emailpnl.com	25
559	mx0.fortion.net	25
560	mx.soverin.net	25
561	email.cnhi.com	25
562	mx1.fiercebadger.com	25
563	mx.noip.com	25
564	sgrmgw5.swatchgroup.com	25
565	sgrmgw6.swatchgroup.com	25
566	spamgw.blueweb.co.kr	25
567	mx03.puc.rediris.es	25
568	mx04.puc.rediris.es	25
569	mx1.dandomain.dk	25
570	mx1.spamfiltering.com	25
571	chocobo.mxrouting.net	25
572	mx1.suremail.cn	25
573	mx2.suremail.cn	25
574	mx3.suremail.cn	25
575	mx4.suremail.cn	25
576	a2.spambusters.email	24
577	smtp1.lerelaisinternet.com	24
578	smtp2.lerelaisinternet.com	24
579	mxbackup1.junkemailfilter.com	24
580	mx1.megamailservers.com	24
581	mx2.mail-scanner.eu	24
582	mail-pt.securemail.pro	24
583	mx10.omc.net	24
584	mail4.ethionet.et	24
585	mx2.zohocloud.ca	24
586	mx3.zohocloud.ca	24
587	mx1.friendfinder.com	24
588	mx2.friendfinder.com	24
589	mx3.friendfinder.com	24
590	smtp1-inki.e-i.net	24
591	smtp1-insi.e-i.net	24
592	mgf.cybermail.jp	24
593	mx-aol.mail.gm0.yahoodns.net	24
594	gw-spam.mailwood.com	24
595	mx-in04b.natrohost.com	24
596	mx01.ofis.net	24
597	mx.truemail.it	24
598	mail-in1.rian.ru	24
599	mail-in2.rian.ru	24
600	mx1.fortion.net	24
601	mx-in.kommunale.it	24
602	mx1.antispam-login.net	24
603	mx2.antispam-login.net	24
604	mx2.dandomain.dk	24
605	mx1.mailhop.us	24
606	chocobo-relay.mxrouting.net	24
607	gateway.aos.rw	24
608	extern-gateway.innogames.de	24
609	serwer1429664.home.pl	24
610	mx.eivoittoa.fi	24
611	my-mx.email-protect.gosecure.net	23
612	mx2.megamailservers.com	23
613	mx3.megamailservers.com	23
614	fallbackmx.spamservice.nl	23
615	lastmx.spamservice.nl	23
616	mx11.omcnet.de	23
617	rk2.comju.de	23
618	mx1.earfulwolf.com	23
619	moose.mxrouting.net	23
620	moose-relay.mxrouting.net	23
621	mx-in04.natrohost.com	23
622	inbound.mail.naiadsystems.com	23
623	mail2.filteredmx.net	23
624	mx1.smashtic.com	23
625	mxh.eu.mpssec.net	23
626	mxi.eu.mpssec.net	23
627	mx2.fortion.net	23
628	smtp.sarenet.es	23
629	mxf.eu.mpssec.net	23
630	mxg.eu.mpssec.net	23
631	mx1.ravingchamois.com	23
632	smartmail1.fednet.gov.ae	23
633	smartmail2.fednet.gov.ae	23
634	mx1-mailcontrol.conova.com	23
635	mx2-mailcontrol.conova.com	23
636	mx3-mailcontrol.conova.com	23
637	mx4-mailcontrol.conova.com	23
638	mail.hostalo.it	23
639	mx.hitcluster.com	23
640	mailfilter.hibox.biz	23
641	apache.mk.ru	23
642	mx.inbox.eu	22
643	mta.hosts.net.nz	22
644	mx.spamservice.nl	22
645	mx76.antispam-post.ru	22
646	mgk.cybermail.jp	22
647	mx2.lite-host.su	22
648	mail.ssonet.nl	22
649	mail2.ssonet.nl	22
650	mx.spamorez.ru	22
651	mx.zoho.jp	22
652	mx2.zoho.jp	22
653	mx3.zoho.jp	22
654	mail01.phoenixgroup.eu	22
655	mail02.phoenixgroup.eu	22
656	mail03.phoenixgroup.eu	22
657	mail04.phoenixgroup.eu	22
658	mgw.gov.kz	22
659	dmeas11.imail.scig.gov.hk	22
660	dmeas12.imail.scig.gov.hk	22
661	pmeas11.imail.scig.gov.hk	22
662	pmeas12.imail.scig.gov.hk	22
663	mail1.rit.ee	22
664	mail3.rit.ee	22
665	my.mailbux.com	22
666	s2vg300mr01.pzd-svn.de	22
667	s2vg300mr02.pzd-svn.de	22
668	mail1.filteredmx.net	22
669	mail3.filteredmx.net	22
670	mx1.maileroo.com	22
671	mx2.maileroo.com	22
672	mx4.eganet.go.tz	22
673	mx20.vwgroup.com	22
674	mx1.belwue.de	22
675	mx1.mailhop.co	22
676	mx1.mailhop.co.uk	22
677	mx1.promail.com.tr	22
678	mx2.promail.com.tr	22
679	mail.tehila.gov.il	22
680	pop2.ocnk.net	22
681	mx1.jimdo.com	22
682	mx2.jimdo.com	22
683	cr1.cylex.de	22
684	mail.mycylex.de	22
685	accor.in.tmes.trendmicro.eu	21
686	a.mx.mayfirst.org	21
687	b.mx.mayfirst.org	21
688	c.mx.mayfirst.org	21
689	mx1.alastyr.com	21
690	mail.academiadasapostas.com	21
691	mx20.profesionalhosting.com	21
692	mx10.profesionalhosting.com	21
693	factorix.sdv.fr	21
694	blackhole.scw-tem.cloud	21
695	mx1.cloudaccess.net	21
696	mx2.cloudaccess.net	21
697	mx-mibc-fr-09.mailinblack.com	21
698	smtp.tmgrup.com.tr	21
699	mx.turktelekomeposta.com	21
700	mx1.antispam-post.ru	21
701	mwbgw1.ocn.ad.jp	21
702	mwbgw2.ocn.ad.jp	21
703	sns.nethost.sk	21
704	mx01.windstream.net	21
705	mail.framasoft.org	21
706	mx-mibc-fr-03.mailinblack.com	21
707	inbound-reply.s1.exacttarget.com	21
708	smtp-in0.prod0.webspace.bz	20
709	mxbackup2.junkemailfilter.com	20
710	aspmx.whoisworks.com	20
711	mail.endora.cz	20
712	mx32.antispam-post.ru	20
713	forwarder.moddies.be	20
714	mfwd.eurodns.com	20
715	mg.cybermail.jp	20
716	mx-4.pobox.com	20
717	mx-5.pobox.com	20
718	mfwd.ebrandservices.com	20
719	mx2.alastyr.com	20
720	mx.portsit.se	20
721	mx.portsit.com	20
722	mx.inbound.elasticemail.com	20
723	eu.mx1.mailanyone.net	20
724	eu.mx2.mx25.net	20
725	eu.mx4.mx25.net	20
726	mxbackup1.svrsh.com	20
727	mx01.goneo.de	20
728	mx02.goneo.de	20
729	mx1.hostcreators.sk	20
730	mx2.hostcreators.sk	20
731	smtp.sparkpostmail.com	20
732	mx6.eganet.go.tz	20
733	mx02.ofis.net	20
734	mx01.mi.com.co	20
735	mail.cco.in.ua	20
736	mailas02.clog.jp	20
737	mx.nameweb.biz	20
738	mail.tubecj.com	20
739	spamguard1.mxserver.ro	20
740	spamguard2.mxserver.ro	20
741	mx.sina.net	20
742	mail.messaging.microsoft.com	20
743	bounce.argewebhosting.nl	20
744	mx1c51.megamailservers.com	20
745	zmx33.zimbra.in.ua	20
746	mx0002.neo.space	20
747	mx0001.neo.space	20
748	mx1.reg365.net	20
749	mx2.reg365.net	20
750	mailmx0001.rlp.de	20
751	mailmx0002.rlp.de	20
752	mailmx0003.rlp.de	20
753	mailmx0004.rlp.de	20
754	mxprimary.spamfilterserver.com	20
755	mxfallback.spamfilterserver.com	20
756	rcmx3.roscongress.org	20
757	mx1.flockmail.com	20
758	mx2.flockmail.com	20
759	mx1.hanami.run	20
760	mx2.hanami.run	20
761	mailscanner01.zoner.fi	20
762	mailscanner02.zoner.fi	20
763	mail2535230.us.to	20
764	mx.vk.com	20
765	smtp-in1.prod0.webspace.bz	19
766	mail6.finarea.ch	19
767	yandex.net	19
768	mxs.hoster.ru	19
769	alf1.aspmx.whoisworks.com	19
770	alf2.aspmx.whoisworks.com	19
771	safari.mxrouting.net	19
772	mx.portsit.net	19
773	mail-de.maxcluster.net	19
774	monday.mxrouting.net	19
775	eu.mx3.mailanyone.net	19
776	primary.us.etp.fireeyegov.com	19
777	alt1.us.etp.fireeyegov.com	19
778	mx1.spamorez.ru	19
779	mxbackup2.svrsh.com	19
780	mx-avas.mvmnet.com	19
781	mx.bpn.ge	19
782	mx2.auto-vision.ru	19
783	mxbackup01.ofis.net	19
784	ign-mx1.webglobe.com	19
785	ign-mx2.webglobe.com	19
786	mail1.olgdns.eu	19
787	mia1-load.supramail.com.br	19
788	mx1.gigahost.dk	19
789	mx2.gigahost.dk	19
790	mx3.gigahost.dk	19
791	mx01.govmail.gov.jo	19
792	mx02.govmail.gov.jo	19
793	mx.xmission.com	19
794	mx3c51.megamailservers.com	19
795	ag1.cesnet.cz	19
796	ag2.cesnet.cz	19
797	mr1.volkswagen.de	19
798	mr2.volkswagen.de	19
799	mr3.volkswagen.de	19
800	mr4.volkswagen.de	19
801	mx.ct.mbox.net	19
802	mx.junkemailfilter.org	19
803	filter.premiumantispam.nl	19
804	fallback.premiumantispam.nl	19
805	mx2.belwue.de	19
806	mx3.belwue.de	19
807	mx4.belwue.de	19
808	parse.mailjet.com	19
809	selmx5.roscongress.org	19
810	sgc.hsplus.email	19
811	smtp1.osuosl.org	19
812	smtp2.osuosl.org	19
813	smtp3.osuosl.org	19
814	smtp4.osuosl.org	19
815	antispamawn.thaicloudsolutions.com	19
816	mx.ilait.se	19
817	mail03.gov.cy	19
818	mail02.fw.porsche.de	19
819	mail.fw.porsche.de	19
820	sv62.ifastnet11.org	18
821	mx1.vevida.com	18
822	mx2.vevida.com	18
823	mx3.vevida.com	18
824	backup-mx.vevida.com	18
825	mx1.mijn.host	18
826	mx2.mijn.host	18
827	antispam04.pensomail.com.br	18
828	mx4.funlife.cz	18
829	mx-dfw.smtp.directrouter.com	18
830	mail.anonaddy.me	18
831	reply.s50.exacttarget.com	18
832	mx-in03b.natrohost.com	18
833	mx3.mailinghosting.com	18
834	mail.hostiservices.com	18
835	mx-wdc-1.ssnc-corp.cloud	18
836	mr.pavietnam.vn	18
837	mail1.qlc.co.in	18
838	mail2.qlc.co.in	18
839	mail3.qlc.co.in	18
840	reply.s13.exacttarget.com	18
841	mx1.dnsxperta.com	18
842	secmail.iap.socgen.com	18
843	nomail.r01.ru	18
844	mx4.antispam-post.ru	18
845	mx.fusemail.net	18
846	mx.inet.vn	18
847	mxacloud02.imatrix.co.jp	18
848	mail.schroederdennis.de	18
849	mxz1.klarna.com	18
850	mxz2.klarna.com	18
851	mxz3.klarna.com	18
852	smtp01.wmaker.net	18
853	smtp02.wmaker.net	18
854	mx-10.us-east.atmailcloud.com	18
855	fortispam.cedia.org.ec	18
856	smtp1.speednames.com	18
857	cloudscan24.ilger.com	18
858	gwmail.ktbizoffice.com	18
859	mail.casinocontroller.com	18
860	postrelay1.lrz.de	18
861	postrelay2.lrz.de	18
862	smtp2.speednames.com	18
863	mx.junkemailfilter.net	18
864	mail.amamultimedia.com	18
865	inbound-reply.s7.exacttarget.com	18
866	mail-relay-1.nethost.cz	18
867	smtp-relay.corpex-net.de	18
868	mx2.bitrixsoft.com	18
869	mailgw.mts.rs	18
870	mx2.freeola.com	18
871	mx3.freeola.com	18
872	mx4.freeola.com	18
873	mx5.freeola.com	18
874	smtp.egcloud.gov.eg	18
875	mail2.p24.hu	18
876	mailscanner.powerhosting.dk	18
877	backup-mx.powerhosting.dk	18
878	fallback.axc.eu	18
879	cesp00-in.mss.bi.zone	18
880	mta5.am0.yahoodns.net	18
881	mta6.am0.yahoodns.net	18
882	mta7.am0.yahoodns.net	18
883	mx.dka.mailcore.net	18
884	spam.seoul.go.kr	18
885	spam2.seoul.go.kr	18
886	mail.lottery.ltd.uk	18
887	mail.advameg.com	18
888	mx-in-1.webreus.nl	17
889	mx1.ex.360.cn	17
890	mx4.vevida.com	17
891	mx1.sparkspace.huaweicloud.com	17
892	mx2.sparkspace.huaweicloud.com	17
893	mx1.redhat.com	17
894	safari-relay.mxrouting.net	17
895	mail.mmmmmmmm.pw	17
896	mx1.de.opalstack.com	17
897	mx2.de.opalstack.com	17
898	rx1.sparkpostmail.com	17
899	rx2.sparkpostmail.com	17
900	rx3.sparkpostmail.com	17
901	eu1.workspace.org	17
902	mx19-1.mycloudmailbox.com	17
903	mx19-2.mycloudmailbox.com	17
904	b1234.mx.srv.dfn.de	17
905	c1234.mx.srv.dfn.de	17
906	mail.eppg.com	17
907	alt2.us.etp.fireeyegov.com	17
908	alt3.us.etp.fireeyegov.com	17
909	mx01.logixmx.com	17
910	mx02.logixmx.com	17
911	mx-lon.smtp.directrouter.com	17
912	mail2.anonaddy.me	17
913	mx-in03.natrohost.com	17
914	mx1.greentube.com	17
915	mx2.greentube.com	17
916	mx3.plus.pl	17
917	mx4.plus.pl	17
918	mx3.netregistry.net	17
919	mx2.netregistry.net	17
920	mx-ykt-1.sscinc.com	17
921	mx1.em.dingtalk.com	17
922	mx2.em.dingtalk.com	17
923	noreply.qemailserver.com	17
924	fm.telconet.net	17
925	gw117173.fortimail.com	17
926	mx1.efwd.spaceship.net	17
927	captmx-re20.bizflycloud.vn	17
928	captmx-re30.bizflycloud.vn	17
929	captmx-re40.bizflycloud.vn	17
930	mail.mosby.com	17
931	ign-mx3.webglobe.com	17
932	ign-mx4.webglobe.com	17
933	mdn.corpemail.net	17
934	mdn.corp-email.cn	17
935	hecker.web-eci.com	17
936	mx.yourpaysitepartner.com	17
937	mail2.olgdns.com	17
938	mx3.daouoffice.com	17
939	reply.s10.exacttarget.com	17
940	mercure.credit-agricole.fr	17
941	mx4c51.megamailservers.eu	17
942	mx-in-hfd.apple.com	17
943	mx-in-vib.apple.com	17
944	mx-in1.euronic.fi	17
945	mx-in2.euronic.fi	17
946	mx-in05.natrohost.com	17
947	mail1.seliton.com	17
948	mx1.secure.ly	17
949	mx1.mailhop.org	17
950	smtp.webnames.ca	17
951	mail2.casinocontroller.com	17
952	vip-mail.superhosting.cz	17
953	mail.nexylan.net	17
954	mx.junkemailfilter.com	17
955	relay.mail.sec-provider.de	17
956	mail.net4india.com	17
957	dhl-com.fortimailcloud.com	17
958	rtmx2.roscongress.org	17
959	mailasp.itcomp.tech	17
960	backup.mail.profiwh.com	17
961	monday-relay.mxrouting.net	17
962	fml01.sc-kanagawa.jp	17
963	mx1.inno.tech	17
964	mx2.inno.tech	17
965	mx3.inno.tech	17
966	zalc.e-purifier.com	17
967	zalj.e-purifier.com	17
968	mx3.eganet.go.tz	17
969	mx0.mailinblack.com	17
970	dns10977.phdns5.es	17
971	mx1.chengmail.cn	16
972	mx2.chengmail.cn	16
973	mxa.townsquaremedia.com	16
974	mx-in-2.webreus.nl	16
975	mail.jetmail.email	16
976	mx1.nethely.hu	16
977	mx2.nethely.hu	16
978	inbound.registeredsite.com	16
979	mx01.263xmail.com	16
980	mx1.greenhost.nl	16
981	mx2.greenhost.nl	16
982	a1234.mx.srv.dfn.de	16
983	mx11-new.vatican.va	16
984	mx12-new.vatican.va	16
985	mx20.vatican.va	16
986	mx21.vatican.va	16
987	us2-smtp-mx1.titanhq.com	16
988	us2-smtp-mx2.titanhq.com	16
989	mx3.em.dingtalk.com	16
990	mail2.motorpresse.de	16
991	mail.netdirect.cz	16
992	mx.c2.icoremail.net	16
993	mx.us.mailmarshal.cloud	16
994	mx.sigmanet.lv	16
995	mx2.bgdns.net	16
996	fallback1.server.eu	16
997	fallback2.server.eu	16
998	mx1.cpmx.co.za	16
999	mail.system.digitalartscloud.com	16
1000	mx1.menara.ma	16

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	\234\176\128\235\179\180\236\158\144\236\178\180\237\151\152\235\139\168.com
2	port-arthur-historic-site-management-authority-mx1.firstcloudsecurity.net
3	port-arthur-historic-site-management-authority-mx2.firstcloudsecurity.net
4	cubic-transportation-systems-australia-mx2.firstcloudsecurity.net
5	cubic-transportation-systems-australia-mx1.firstcloudsecurity.net
6	nlg-nhs-uk.mail.protection.outlook.com.disabled-dangler-101225
7	darpagcchigh-mail-onmicrosoft-us.mail.protection.office365.us
8	manak-waste-management-private-ltd-mx2.firstcloudsecurity.net
9	manak-waste-management-private-ltd-mx1.firstcloudsecurity.net
10	mx1.123-regmmailsec.protonmail.chailsec.protonmail.ch.co.uk
11	df-nu4a-g8rhv-jl689-g9c89-ruukm-t7dhr.in.tmes.trendmicro.eu
12	skeletal-triceratops-g8ku8ehowd09a0s8ppapxcdf.herokudns.com
13	p3plzcpnl502916.prod.phx3.secureserver.net.eco-reglalos.com
14	8ad2f72d-b2c4-4426-93fd-baacf7213b2d.in.tmes.trendmicro.eu
15	knowbe4-site-verification=34b9a58212e47bbcdf835890f6facdda
16	manulifesinochem-com02b.mail.protection.partner.outlook.cn
17	europeanchamber-com-cn.mail.protection.partner.outlook.cn
18	canaancreative-com01e.mail.protection.partner.outlook.cn
19	nfi34bdspmurbud57axm3w3xj2oyegddbnn6576ooea2jqnvu2mq.mx-
20	neusoftmedical-com01i.mail.protection.partner.outlook.cn
21	accenturefederaldefense-com.mail.protection.office365.us
22	audifawnev-com-cn01bb.mail.protection.partner.outlook.cn
23	printondemand-worldwide.com.pri-mx.uk0101.smtproutes.com
24	lb-sensproxy-2213375-dc68d533ade4.kr-gov.lb.naverncp.com
25	leidseschouwburgstadsgehoorzaal-nl04b.c-v1.mx.microsoft

Show rows 26 – 100

#	MX target (rare singleton)
26	u003d1a3b487390464833982a65fae59682b8.pamx1.hotmail.com
27	porschepreview-cn01i.mail.protection.partner.outlook.cn
28	sheltered-wildebeest-nw4f5n6yfgkz10hjq0e2b03r.herokudns
29	etpr3nvk46n27vcc4juimkc7lxqosohb2zurr75mhylme5ye3awa.mx
30	western-suburbs-leagues-club-mx1.firstcloudsecurity.net
31	nospamcloudserver.germanywestcentral.cloudapp.azure.com
32	western-suburbs-leagues-club-mx2.firstcloudsecurity.net
33	ipolaristech-com02b.mail.protection.partner.outlook.cn
34	261fab891c9e30b9a8437b2307e7e67ebbfeee85.msv1.invalid
35	7544859033090d52a1be915fe96b1ec34f4dfd58.msv1.invalid
36	be7c5e09a4d9047e88c98c8bdd5c0306855692b8.msv1.invalid
37	bc372757c311901487f6c203422338a0297105f9.msv1.invalid
38	3aca052794b229b9bc1b416f6993402b2b828e45.msv1.invalid
39	b894a10f9d664f0b272df24349d0136fba05a89b.msv1.invalid
40	8fca991f22bf0d3d9888adf9a9f177956ff29643.msv1.invalid
41	638d21520d5d8632ca41f2350704980f00eee5ee.msv1.invalid
42	1a326408be933c5f8ebd6551caad02b32d0522fc.msv1.invalid
43	a9113b4395021c9cc23547ba026fd9f7b2262a20.msv1.invalid
44	abdf4c2da467191154ac33e376c4b147dc19c183.msv1.invalid
45	51e1151fac65ad93d2c3cb907f9a1e1bb5976586.msv1.invalid
46	e1373a12bca10839245327b9929bbbb41f14a8b3.msv1.invalid
47	c37b41cc2aa83c50b8571a4fc41db855c664ecb8.msv1.invalid
48	86da5df266ee85ba1c9b2e19f890526f1191355e.msv1.invalid
49	4b21ca12bd08ff22911a3537cf16967c602f815c.msv1.invalid
50	e7a49c039e315cecff2d44801582cffd32c15504.msv1.invalid
51	explorationpub-com.mail.protection.partner.outlook.cn
52	e57689ebf1cee2dcc74ca9695ba1a35f5249a903.msv1.invalid
53	52f27914d6785f1569d999124b030c5d757f88dc.msv1.invalid
54	printondemand-worldwide.com.bak-mx.uk0101.smtpbak.com
55	b7d2174f2e1b3ef1065ffa8a05f24e3ca87487e4.msv1.invalid
56	279c75a743b1712505623de1926da99446f03967.msv1.invalid
57	0a99a5a2e57678a1b6734c49394b078db87b621c.msv1.invalid
58	e17e3996f364c6cdecf3bd80e4c2687defe6e40d.msv1.invalid
59	d3289eaaa594de2bf98e995630fdf76eb646bd67.msv1.invalid
60	34de6bfcee5eaa0618b2993e691f50010e064aad.msv1.invalid
61	c7d3d7276f30dc72efbeb8e54423b1b47f63c58c.msv1.invalid
62	2a3139bde0fa73af719ed58cd4bc476dab5a81cc.msv1.invalid
63	voipdnsservers-com.mail.protection.outlook.comook.com
64	35eccb37124455cf58268be2c6f4b8f6e8437873.msv1.invalid
65	mercedesbenz-cn02b.mail.protection.partner.outlook.cn
66	7a1b696a13d31b9dd635db9c58d1f1c23c2c8288.msv1.invalid
67	b9b6ae914169a5a1688b1ae10978544884baaeb2.msv1.invalid
68	6b2abbb43f243b33acbb3ee840a65711ba425d4b.msv1.invalid
69	64e72857b06d310c34fb9bc4c83301e58346dda5.msv1.invalid
70	dd65647d11fb1053fa50107650b42fc91a436e09.msv1.invalid
71	23a61b54849a99e548624c09d1cdddef7ffb2764.msv1.invalid
72	90567ad2edb4ac9680d76a5d4492522415dc356e.msv1.invalid
73	9454fb2379b964a3496c91542921806588522fac.msv1.invalid
74	f59062e299f55da9447ced93e0ca43a2524e3386.msv1.invalid
75	d8ef932105e6cdcd8d95d568e0ceb61e012b76b4.msv1.invalid
76	8128664d7b9f7560c069c1bc8e6e2288e53721dc.msv1.invalid
77	7d647202e4a762b842051e7ec60ff2fbd7fa2867.msv1.invalid
78	c963dca136a4bce8212792ad4022794f77140e27.msv1.invalid
79	5630e8ec42dcf18d9f086f6c16eb2667db34ace6.msv1.invalid
80	8a67419f6a694a1ec48efaa808ecca68e0bee47d.msv1.invalid
81	0e52eafae7d1afa59efc92fe1a4ff3276f8eed08.msv1.invalid
82	7312c3dbeed587e1ca48d18b0132c7c7d3d449d0.msv1.invalid
83	porschepcn-com01i.mail.protection.partner.outlook.cn
84	f32ulet7jexwiwmrwipot2hs332uejyx5q5nwf3ggp77wer7utca
85	neueimpulseverlag-de01b1b.mail.protection.outlook.de
86	5c7am4rrhs7xh7sgmu74qjaqd4phx2qifzbv6jl3i3xz3zhjqqqq
87	\234\176\149\235\130\168\235\167\155\236\167\145.net
88	3osdx5cysr5ezqynjk3rxbwfxkoqwt47ek32cdcy7uar65mfindq
89	3aas5bdlzoabws5g7mber6wtuyuvqjldemho2xwpx2pjf36yejoa
90	gdsservices-com0i.mail.protection.partner.outlook.cn
91	outdoormaster-com.mail.protection.partner.outlook.cn
92	qctzdy9yn1z9q3cj.gpqh6jl7d4xobee0.pki-validation.com
93	sailtraininginternational-org.mx1-uk.mailanyone.net
94	langotech-com01c.mail.protection.partner.outlook.cn
95	digitalengineeringmagazin-de01i2i.v-v1.mx.microsoft
96	hillstonenet-com.mail.protection.partner.outlook.cn
97	decathlon-com-cn.mail.protection.partner.outlook.cn
98	sailtraininginternational-org.mx2-uk.mailanyone.net
99	switchbot-com01e.mail.protection.partner.outlook.cn
100	emprisecorporation-com.mail.protection.office365.us

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	25 758
2	de	5 661
3	net	5 204
4	ru	3 824
5	org	2 899
6	pl	1 983
7	it	1 642
8	jp	1 636
9	fr	1 617
10	nl	1 557
11	cz	1 319
12	co.uk	1 216
13	com.br	1 100
14	eu	909
15	co.jp	784

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 2026-05-04. Aggregates only — raw data is deleted after analysis per the OpenINTEL data agreement.