Find every subdomain
of a domain.

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

16 hosts · 203 ms

HostCertsFirst seenLast seen
mailsuite.com 2 2025-10-20 2026-09-20
e.mailsuite.com 3 2025-11-05 2026-10-06
internal.e.mailsuite.com 3 2025-11-05 2026-10-06
dev.e.mailsuite.com 3 2025-11-05 2026-10-06
testing.mailsuite.com 3 2025-10-20 2026-09-20
outlook.mailsuite.com 1 2025-12-21 2025-12-21
influemail.mailsuite.com 5 2026-05-01 2026-08-29
mcp.mailsuite.com 1 2026-06-03 2026-06-03
help.mailsuite.com 3 2026-04-12 2026-09-12
spam-checker.mailsuite.com 3 2026-04-20 2026-09-20
internal.spam-checker.mailsuite.com 1 2026-05-26 2026-05-26
next-steps-demo.spam-checker.mailsuite.com 8 2026-05-07 2026-07-11
test.spam-checker.mailsuite.com 1 2026-02-18 2026-02-18
links.mailsuite.com 5 2026-04-24 2026-08-24
superset.mailsuite.com 2 2026-03-18 2026-08-18
www.mailsuite.com 1 2025-12-21 2025-12-21

Programmatic access: API GET /v1/hosts/mailsuite.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/mailsuite.com.