Deliverability briefing, Saturday, 15 August 2026
No deliverability stories today: DMARC enforcement climbs to 88.1%
There is no new deliverability story today. Instead, the news is in the numbers. DMARC enforcement across Emailchaser's panel of 499 business domains rose to 88.1%, up 0.4 percentage points from 87.9% on 10 August 2026.
Inbox Rules Index
Measured Saturday, 15 August 2026
Emailchaser measured 497 of 499 panel domains today. DMARC enforcement reached 88.1%, up 0.4 percentage points from 87.9% on 10 August 2026. Strict SPF sits at 42.9% and MTA-STS at 4.8%, both still minority practices. This is a measurement of the domains you send to, not a report on your own sending.
Who filters their mail: Proofpoint 33.8%, Microsoft 365 25.8%, Google Workspace 18.9%, Self-hosted or other 10.1%.
Changed since 2026-08-10: duke-energy.com DMARC policy none to quarantine; riteaid.com DMARC policy none to quarantine; thermofisher.com mail provider Proofpoint to Self-hosted or other; tractorsupply.com SPF policy strict to soft.
497 of 499 panel domains resolved today. A fixed panel of real business domains, measured every day over public DNS. This is a measurement of the domains a sender emails, not of Emailchaser customer sending data.
Questions senders asked today
What percentage of domains enforce DMARC today?
88.1% of the 497 measured domains enforce DMARC with a policy of quarantine or reject, up from 87.9% on 10 August 2026, a rise of 0.4 percentage points.
What is the weakest sector for DMARC enforcement today?
Education, at 57.1% enforcement across 28 measured domains. Every other sector measured sits at 79.5% or higher, with SaaS the strongest at 97.6% across 126 domains.
Did any domain change its DMARC policy today?
Yes. duke-energy.com and riteaid.com both moved from no policy to quarantine. tractorsupply.com's SPF policy loosened from strict to soft, a step in the wrong direction.
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