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.

14 hosts · 211 ms

Download CSV
HostCertsFirst seenLast seen
mailup.com 15 2026-03-09 2026-08-31
*.mailup.com 21 2025-09-22 2026-09-22
*.data.mailup.com 2 2025-09-04 2026-08-05
sfmiddleware.mailup.com 5 2026-04-29 2026-08-26
staging.mailup.com 8 2026-06-14 2026-10-10
trk.mailup.com 2 2026-04-02 2026-09-02
*.trk.mailup.com 2 2026-04-02 2026-09-02
sgtm.mailup.com 5 2026-04-25 2026-10-05
go.mailup.com 8 2026-05-11 2026-09-06
webinar.mailup.com 5 2026-05-09 2026-09-06
tr.mailup.com 2 2026-04-03 2026-09-03
*.tr.mailup.com 2 2026-04-03 2026-09-03
services.mailup.com 5 2026-05-14 2026-09-11
new.mailup.com 7 2026-06-06 2026-10-04

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