Email security adoption, November 2026
How the top 10,000 domains in the public Tranco list set up their email in November 2026.
Key figures
- 68% of the top domains publish a DMARC record.
- 31% use the policy p=reject.
- 76% publish an SPF record.
- 54% have a DKIM key under a common selector (a lower estimate).
- 3% publish an MTA-STS policy.
- 10% publish a BIMI record.
This is the first month in the series.
More breakdowns
Notes
- We scanned 99% of the list this month.
- DKIM figures are a lower estimate, because we try common selector names only.
- Percentages are rounded to whole numbers.
- To look up a single domain, use the domain email check.
These figures describe which records domains publish. They are not a security rating of any domain or group.
How we measure
Each month we read the public DNS records of the top 10,000 domains in the public Tranco list. We look for MX, SPF, DKIM, DMARC, MTA-STS and BIMI records. We read public DNS only. We never connect to these domains' mail servers and never send them email.
A month is published only if we scanned at least 90% of the list. Any group with fewer than 50 domains is not shown. Domains of Mailbux customers are left out.
DKIM is checked under common selector names only, so its numbers are a lower estimate. All percentages are rounded to whole numbers, so totals may not add up to exactly 100%.
Domains that publish no mail records count as not adopting.
Last updated 10.11.2026 20:35 IL (10.11.2026 18:35 UTC)