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Microsoft 365 among Y Combinator companies
Microsoft 365 was detected on 279 of 5,386 crawled Y Combinator company websites, a share of 5.2%.
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 Microsoft 365 | Share |
|---|---|---|---|
| Inc 5000 (2026) | 4,888 | 2,258 | 46.2% |
| Y Combinator companies | 5,386 | 279 | 5.2% |
| Fortune 500 | 472 | 171 | 36.2% |
| Unicorns | 1,000 | 199 | 19.9% |
| SaaS companies | 8,173 | 1,773 | 21.7% |
| Tranco top 10,000 | 1,572 | 260 | 16.5% |
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 2 of the 5 Email Hosting tools published for this group.
Software used by Y Combinator companies · Email Hosting across all groups
Source: Installmap crawl, 4 September 2026
Badge
<a href="https://installmap.com/groups/yc/microsoft-365"><img src="https://installmap.com/badges/yc/microsoft-365.svg" alt="Microsoft 365 runs on 279 of 5,386 crawled YC companies (5.2%)"></a>
[](https://installmap.com/groups/yc/microsoft-365)
Badge URL: https://installmap.com/badges/yc/microsoft-365.svg · all badges.
Cite this
Installmap, Microsoft 365 among Y Combinator companies, crawl of 4 September 2026, https://installmap.com/groups/yc/microsoft-365.
Other Email Hosting tools in this group
- Google Workspace 79.1%
- Zoho Mail 0.6%
- GoDaddy Email 0.2%