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.

17 hosts · 217 ms

HostCertsFirst seenLast seenDNS
bouygues-telecom.fr 1 2026-07-30 2026-07-30 nodata
mx1.bouygues-telecom.fr 1 2026-01-27 2026-01-27 ok
mx2.bouygues-telecom.fr 1 2026-01-27 2026-01-27 ok
imap4.bouygues-telecom.fr 2 2025-07-16 2026-05-21 ok
imap4-b.bouygues-telecom.fr 2 2025-07-16 2026-05-21 ok
relay-btbd-b.bouygues-telecom.fr 1 2026-01-05 2026-01-05 ok
imap-b.bouygues-telecom.fr 2 2025-07-16 2026-05-21 ok
relay-btbd-1b.bouygues-telecom.fr 1 2026-01-05 2026-01-05 ok
relay-btbd-2b.bouygues-telecom.fr 1 2026-01-05 2026-01-05 ok
imap.bouygues-telecom.fr 2 2025-07-16 2026-05-21 ok
www.bouygues-telecom.fr 19 2025-09-23 2026-09-24 ok
mx.bouygues-telecom.fr 1 2026-01-27 2026-01-27 nxdomain
imap4-y.bouygues-telecom.fr 2 2025-07-16 2026-05-21 ok
relay-btbd-y.bouygues-telecom.fr 1 2026-01-05 2026-01-05 ok
imap-y.bouygues-telecom.fr 2 2025-07-16 2026-05-21 ok
relay-btbd-1y.bouygues-telecom.fr 1 2026-01-05 2026-01-05 ok
relay-btbd-2y.bouygues-telecom.fr 1 2026-01-05 2026-01-05 ok

Programmatic access, with DNS A records: API GET /v1/hosts/bouygues-telecom.fr (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/bouygues-telecom.fr.