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.

4 hosts · 274 ms

HostCertsFirst seenLast seenDNS
cloud.mail.stillwater.com 1 2025-09-19 2025-09-19 nxdomain
image.mail.stillwater.com 3 2025-08-29 2026-07-13 ok
click.mail.stillwater.com 1 2025-09-19 2025-09-19 nxdomain
view.mail.stillwater.com 1 2025-09-19 2025-09-19 nxdomain

Programmatic access, with DNS A records: API GET /v1/hosts/mail.stillwater.com (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.stillwater.com.