This is the first release in a new Castle series highlighting email domains associated with fraudulent activity. Our goal is to provide visibility into email infrastructure commonly abused by bots and fraudsters, so that security teams can improve their detection systems.
Each month, we’ll publish a ranked list of domains seen in connection with fake account creation and other types of abuse. These include:
- Known disposable email services
- Custom “throwaway” domains registered for fraud
- Legitimate free email providers with weak anti-abuse mechanisms
Why we're publishing this
Most open-source intelligence sources that track email domain abuse focus exclusively on disposable providers, often by scraping public websites that advertise temporary inbox services. This approach misses a large portion of the threat landscape.
Because Castle protects real-world websites and mobile applications against fraud and bots, we observe not only traffic from well-known disposable domains, but also custom throwaway domains created specifically for abuse. These domains often fly under the radar of traditional disposable email blocklists.
By sharing the domains we’ve detected at scale, we aim to give fraud teams broader visibility into the infrastructure attackers are actually using, not just the obvious sources.
How to use this list
We do not recommend blocking these domains outright. Instead, treat them as risk signals; a domain's presence can be used to score or flag sessions for further evaluation. For example:
- Lower your threshold for additional verification steps
- Combine with behavioral or device fingerprinting data for higher precision
- Monitor for spikes in usage of emerging custom domains
The list below is sorted by volume of malicious activity observed, from highest to lowest.
sweetdoggo.xyz
gamil.com
gmai.com
strelizia.store
gmil.com
emaily.pro
ptct.net
yopmail.com
paradox5m.net
gamerspace.online
jioso.com
bcooq.com
bilola.shop
gmal.com
gamail.com
gemail.com
sexintens.cam
naobk.com
mobilesm.com
clubemp.com
ptiong.com
dpcos.com
insfou.com
gimail.com
ovobri.com
gmali.com
gufum.com
anlocc.com
letterhaven.net
ytnhy.com
buides.com
inveitro.com
gmial.com
provko.com
lesotica.com
nbmbb.com
exclussi.com
movfull.com
poplk.com
hthlm.com
bariswc.com
noroasis.com
soraigc.com
powerery.com
gnail.com
gmaill.com
wapgad.com
nhieuthe.tech
toidibay.tech
evluence.com
hacoi.shop
toannga.tech
ductuan.shop
vanhoc.online
haunexd.com
ngocquan.tech
nhimthoi.tech
avulos.com
sangtam.tech
dungna.tech
lamthe.site
dungbip.tech
truangu.tech
uorak.com
xuananhheathcare.com
mcpsmd.net
huudung.store
chieudichoi.tech
quannhue.xyz
vanhoc.tech
vanhoc.xyz
ntd6879.com
gimal.com
androisupper.com
luong500.tech
xuananh-healthcare.com
roomiry.com
dongha.tech
toandz.tech
eligou.com
vanthe.store
gamebcs.com
anhtu.shop
aenhatrang.com
hikuhu.com
gmeil.com
boyaga.com
birige.com
amgens.com
gail.com
bigdick.baby
indigobook.com
thetechnext.net
resonp.com
azuretechtalk.net
polkaroad.net
schuta.com
mailinator.com
logsmarter.net
sharklasers.com
hi2.in
asciibinder.net
dreamclarify.org
telegmail.com
themodish.org
fabricoak.com
embarqmail.com
ecoutlook.com
diigimon.com
hotmai.com
sute.jp
byom.de
equivoeomail.ru
homail.com
yanemail.com
unselected.email
bmail.com
thefluent.org
gemil.com
juno.com
daouse.com
puedemail.com
qzueos.com
dbmail.com
vafyxh.com
iclod.com
illubd.com
drmail.in
maildrop.cc
bonsoirmail.com
gmaiil.com
cs.com
smykwb.com
earthlink.net
quieresmail.com
wywnxa.com
slanct.com
bltiwd.com
vwhins.com
estabamail.com
osxofulk.com
ipahive.org
jkotypc.com
gmall.com
gmaol.com
dygovil.com
tuamaeaquelaursa.com
ibolinva.com
netscape.net
bonjourfmail.com
mkzaso.com
blizzard.com
knmcadibav.com
haren.uk
inbox.eu
qacmjeq.com
wyoxafp.com
aurevoirmail.com
mailto.plus
qejjyl.com
seamays.com
zvvzuv.com
tilemags.com
exdonuts.com
onetm-ml.com
any.pink
demainmail.com
tidissajiiu.com
zudpck.com
jxpomup.com
wavelix.com
emltmp.com
chromomail.com
gmaul.com
cmhvzylmfc.com
jmail.com
tantalix.com
oulook.com
watefr.com
123.com
bigmir.net
atorymail.com
revocto.com
thedaring.org
pokemail.net
freeml.net
buziaczek.pl
steamvv.com
e-mail.com
g-mail.com
worldnet.att.net
bumail.ru
oegmail.com
luminmil.ru
bolivianomail.com
svk.jp
mailna.co
regardermail.com
hotmal.com
choco.la
boxfi.uk
dropmail.me
maximail.vip
gmaik.com
mozej.com
firemail.at
owleyes.ch
ggmail.com
hotmial.com
lyricslrc.com
grr.la
utiliseremail.com
mailpwr.com
emlhub.com
10mail.org
okiden.co.jp
bientotmail.com
via.tokyo.jp
infinitummail.com
usako.net
spymail.one
hotmil.com
outlok.com
chefalicious.com
aceomail.com
f5.si
zpertz.com
fonkanyaphat.com
lookanmail.store
turbonova.xyz
barid.com
mechanorecefmus.ru
satpmail.site
franklinhost.in
yourm.cn
sabesmail.com
fivemrockie.eu
yanag.online
avengremail.com
mesocfmus.ru
writeme.live
thebklmain.xyz
liopdacurier.ro
steamuuu.com
azsxc.com
onelettersmail.com
xuananh-heathcare.com
koplmail.store
satpmail.store
jollypost.xyz
guangp.cn
lookanmail.site
gopostal.top
bklnmain.xyz
r1accounts.online
mailbuddies.xyz
qinianstm.com
quantumdreamer.xyz
allgrounder.com
femboys.asia
mmoko.com
pogomail.store
motakai.store
whitexmail.xyz
merepost.com
longlx.xyz
bkmmain.xyz
deoxidizer.org
mailmunchkins.xyz
postypals.xyz
deadstock.cloud
hfdafkfcdbu.shop
bklmaint.xyz
300bucks.net
outlo0k.online
decompensfml.ru
koplmail.site
52you.in
lostspaceship.net
lesterhost.in
5maccounts.com
echoknight.xyz
burpcollaborator.net
zombiesgo.com
bokomail.shop
motakai.online
letters.monster
custom-mail.ru
novajourney.xyz
nebulaxplorer.xyz
message.rest
notlettersmail.com
kiddomail.xyz
n-xs.eu
yopo.win
adbmail.info
lookanmail.fun
michaehost.in
belettersmail.com
funmailbox.xyz
satpmail.shop
desumail.com
koplmail.shop
galaxygas.cc
smardoiu.shop
satpmail.online
happyinbox.xyz
skywardvibes.xyz
blueink.top
cheaprsgolds.icu
bklynmain.xyz
mailboxland.xyz
bkmain.xyz
buddyboxmail.xyz
momoxontop.com
trevorhost.in
bklsmain.xyz
zdzq88.cn
soukwo.com
blkmain.xyz
earthrockies.xyz
zenithventure.xyz
lookanmail.shop
fexbox.org
lunarvoyager.xyz
naihev5.vip
fivemready.shop
gotiai.com
outlo0k.com
fivemquality.online
nebulaseeker.xyz
cosmicwaves.xyz
ixexmail.xyz
outiloook.xyz
submite.win
lookanmail.online
pogomail.site
tinymailbox.xyz
fivemready.org
cheaprsgolds.top
zangaofc.xyz
