~/dnsniffer/issuers/proofpoint·rank #19
▸ How many domains does Proofpoint secure?
50,310
active domains whose current TLS certificate was issued by Proofpoint, as of - 0.02% of all attributed domains.
# rank #19 of all CAs# all records held: 50,429# subdomains: 3# intermediates: 1# United States
~/issuers/proofpoint/history·active domains
50,310
domains secured by Proofpoint on 2026-10-15 · ▲ +26,827 (+114.24%) since 2025-06-30
# y-axis starts at 20.3K, not zero - domain counts move by fractions of a percent a day. Dashed segments are estimated: reconstructed from certificate first-seen dates before daily snapshots began, not measured on the day.
# change over time
30 days
▲ +9.19%
+4,233 domains
90 days
▲ +12.75%
+5,689 domains
1 year
▲ +22.52%
+9,246 domains
# intermediate CAs
| intermediate | country | domains |
|---|---|---|
| Sectigo Public Server Authentication CA OV R36 | United States | 50,310 |
# faq
- ? How many domains does Proofpoint secure?
- Proofpoint is the certificate authority for 50,310 active domains as of October 15, 2026 - 0.02% of every domain DNSniffer can attribute to an issuer.
- ? Is Proofpoint gaining or losing market share?
- The number of domains secured by Proofpoint has grown by 22.52% over the last year (+9,246 domains).
- ? Which intermediate CAs does Proofpoint sign from?
- We have seen 1 intermediates under Proofpoint, the busiest being “Sectigo Public Server Authentication CA OV R36” with 50,310 domains. The full list, with per-intermediate counts, is on this page.
- ? Where does this number come from?
- DNSniffer ingests Certificate Transparency logs continuously and records the issuer of the most recent certificate seen for each domain, then snapshots the per-issuer count once a day. It measures how much of the live web a CA currently secures, not how many certificates it has issued over its lifetime.