Home / Groups / Y Combinator companies / Cloudflare Email Security
Cloudflare Email Security among Y Combinator companies
Cloudflare Email Security was detected on 5 of 5,386 crawled Y Combinator company websites, a share of 0.1%.
Read from each domain's MX record, and for domains behind an email gateway from its SPF record, not from the homepage.
| Group | Crawled | Running Cloudflare Email Security | Share |
|---|---|---|---|
| Inc 5000 (2026) | 4,888 | 6 | 0.1% |
| Y Combinator companies | 5,386 | 5 | 0.1% |
| Fortune 500 | 472 | n/a | n/a |
| Unicorns | 1,000 | <5 | <5 |
| SaaS companies | 8,173 | 15 | 0.2% |
| Tranco top 10,000 | 1,572 | 5 | 0.3% |
5,386 of 6,133 Y Combinator domains returned a usable record and form the denominator. 5,242 were counted from a rendered homepage crawl on 4 September 2026, 144 from a plain fetch only, and 747 returned no usable record. Email hosting and email security are read from each domain's MX and SPF records, for the same domains. Company list: Y Combinator company directory. <5 means fewer than 5 crawled domains in that group. Rank 3 of the 4 Email Security tools published for this group.
Software used by Y Combinator companies · Email Security across all groups
Source: Installmap crawl, 4 September 2026
Badge
<a href="https://installmap.com/groups/yc/cloudflare-email-security"><img src="https://installmap.com/badges/yc/cloudflare-email-security.svg" alt="Cloudflare Email Security runs on 5 of 5,386 crawled YC companies (0.1%)"></a>
[](https://installmap.com/groups/yc/cloudflare-email-security)
Badge URL: https://installmap.com/badges/yc/cloudflare-email-security.svg · all badges.
Cite this
Installmap, Cloudflare Email Security among Y Combinator companies, crawl of 4 September 2026, https://installmap.com/groups/yc/cloudflare-email-security.
Other Email Security tools in this group
- Proofpoint 0.8%
- Mimecast 0.3%