Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

68 hosts · 309 ms

HostCertsFirst seenLast seenDNS
mail.yahoo.co.jp 1 2025-12-16 2025-12-16 ok
*.mail.yahoo.co.jp 33 2025-06-26 2026-09-03 —
jp.f3000.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f2100.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1020.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f320.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f820.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1030.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1040.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.mg0.mail.yahoo.co.jp 3 2025-08-19 2026-08-07 nxdomain
jp.f3001.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f2101.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1021.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f321.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1031.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f891.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.mg1.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
mx1.mail.yahoo.co.jp 2 2025-10-27 2026-09-08 ok
ybbmx1.mail.yahoo.co.jp 2 2025-10-28 2026-09-08 ok
ymobilemx1.mail.yahoo.co.jp 2 2025-10-28 2026-09-08 ok
zmx1.mail.yahoo.co.jp 2 2025-10-28 2026-09-08 ok
jp.f2102.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1022.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1032.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.mg2.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
mx2.mail.yahoo.co.jp 2 2025-10-27 2026-09-08 ok
jp.f2003.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f2103.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1023.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1033.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.mg3.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
mx3.mail.yahoo.co.jp 2 2025-10-27 2026-09-08 ok
jp.f2004.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f2104.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1024.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1034.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.mg4.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1025.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1035.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.mg5.mail.yahoo.co.jp 3 2025-08-19 2026-08-07 nxdomain
mx5.mail.yahoo.co.jp 2 2025-10-27 2026-09-08 ok
jp.f1026.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1036.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1017.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1027.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1037.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f887.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1018.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1028.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1038.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1019.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1029.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
jp.f1039.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
mta.mail.yahoo.co.jp 2 2025-10-27 2026-09-08 nxdomain
ybbmta.mail.yahoo.co.jp 2 2025-10-28 2026-09-08 nxdomain
ymobmta.mail.yahoo.co.jp 2 2025-10-28 2026-09-08 nxdomain
zmta.mail.yahoo.co.jp 2 2025-10-28 2026-09-08 nxdomain
m.mg.mail.yahoo.co.jp 2 2025-08-19 2026-08-07 nxdomain
cinctool.mail.yahoo.co.jp 3 2026-04-10 2026-09-14 nxdomain
inc-cincvlan.mail.yahoo.co.jp 3 2026-04-10 2026-09-14 nxdomain
imap.mail.yahoo.co.jp 2 2025-07-16 2026-06-16 ok
pop.mail.yahoo.co.jp 3 2025-07-16 2026-06-16 ok
apple.pop.mail.yahoo.co.jp 3 2025-07-16 2026-06-16 ok
ybbpop.mail.yahoo.co.jp 3 2025-07-16 2026-06-16 ok
smtp.mail.yahoo.co.jp 5 2025-08-06 2026-08-11 ok
apple.smtp.mail.yahoo.co.jp 3 2025-08-06 2026-08-10 ok
ybbsmtp.mail.yahoo.co.jp 3 2025-08-26 2026-08-25 ok
jp.mg-test.mail.yahoo.co.jp 3 2025-10-02 2026-08-07 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/mail.yahoo.co.jp (API key for paging).

Shown here: hostnames with a certificate that is valid now or expired within the last 90 days. The full history since 2013 — hostnames whose last certificate expired earlier — is a Pro plan method: GET /v1/hosts-history/mail.yahoo.co.jp.