security.txt (RFC 9116) in Email hosting
It tells a researcher where to report a vulnerability instead of guessing.
15 of 39 companies we measured here publish it, that is 38%. Last checked 2026-10-18.
38% here against 11% across every category we measure. Email hosting sits above the overall share for this criterion.
This page counts companies, not product entries: a company with two products in this category is one company here and two rows below.
Back to security.txt (RFC 9116) across all categories, or to Email hosting.
- Found15
- Not found at checked addresses24
- Not measured3
42 companies in total. Unmeasured companies are excluded from the published share.
Published
Served at /.well-known/security.txt.
No security.txt found.
We reached at least one address for each of these vendors and none of them carried it. That is what we found at the addresses we checked, on the date we checked them, and not a statement about what the vendor has.
| Vendor | What we found |
|---|---|
| All-Inkl | 1 address checkedChecked |
| Atmail | 1 address checkedChecked |
| Biohost | 1 address checkedChecked |
| Greensta | 1 address checkedChecked |
| Hosteurope | 1 address checkedChecked |
| Hushmail | 1 address checkedChecked |
| Kolab | 1 address checkedChecked |
| mailcow | 1 address checkedChecked |
| Maildoso | 1 address checkedChecked |
| Mailfence | 1 address checkedChecked |
| Mailu | 1 address checkedChecked |
| Migadu | 1 address checkedChecked |
| Namecheap | 1 address checkedChecked |
| Netcup | 1 address checkedChecked |
| Posteo | 1 address checkedChecked |
| Purelymail | 1 address checkedChecked |
| Roundcube | 1 address checkedChecked |
| Runbox | 1 address checkedChecked |
| SOGo | 1 address checkedChecked |
| Soverin | 1 address checkedChecked |
| Titan | 1 address checkedChecked |
| Tuta | 1 address checkedChecked |
| Uberspace | 1 address checkedChecked |
| Webgo | 1 address checkedChecked |
Not measured
We could not look at these, or their robots.txt asks us not to. That says something about our measurement, not about them, and they are left out of the percentage above.
| Vendor | What we found |
|---|---|
| Alfahosting | None of the addresses could be reached, so this was not measured.Checked |
| Bluehost Mail | The vendor’s server blocked or rate-limited our crawler, so this was not measured.Checked |
| Zimbra | The vendor’s robots.txt excludes us from at least one of these addresses, so this was not measured.Checked |
Other criteria in Email hosting
- Data processing agreement
- Data location stated
- Status page with history
- Public pricing
- Certifications named
- HTTPS enforced with HSTS
- No third-party tracking before consent
- Named privacy contact
security.txt (RFC 9116) in related categories
Found something we missed? Tell us. A correction moves that vendor into our next nightly run. That run reads the same fixed addresses we check for every vendor, not the address you send.