Where our numbers come from
Every claim, benchmark, or technical specification cited across outsolvi.com traces to a source. This page consolidates the external publications, internet standards, and Outsolvi internal data we cite, so you can check the work.
Not using Outsolvi yet? Every number on this site traces to something you can check. The product applies the same standard to your own sends: each open graded on how likely it was a real person. Start free
The taxonomy below covers Apple MPP documentation, the 2024 bulk-sender authentication rules from Google, Yahoo, and Microsoft, the IETF RFCs defining SPF/DKIM/DMARC/BIMI/one-click unsubscribe, the major enterprise email-scanner vendors' public documentation, the canonical B2B engagement studies, and Outsolvi's own production-data claims with sample sizes.
Apple Mail Privacy Protection (MPP)
Apple Mail Privacy Protection loads remote images for everyone who switches it on, so an Apple Mail open often isn't a read. The sources below document how it works and how much email it touches.
Apple confirms MPP pre-loads remote content on Apple-controlled servers before recipient action.
Apple Mail accounted for 62.26% of the opens Litmus measured in July 2026, across more than a billion opens from all the senders it tracks. Litmus publishes no industry or B2B split.
Industry analysis of MPP impact on open-rate measurement.
Initial MPP launch with iOS 15.
Bulk Sender Authentication Rules (Google + Yahoo + Microsoft)
The February 2024 bulk-sender rules from Google and Yahoo reshaped deliverability requirements for any sender above 5,000 messages/day to consumer addresses.
Official Google sender guidelines including authentication, complaint-rate, and one-click-unsubscribe requirements.
Original announcement of the February 2024 bulk-sender rules; the 0.3% complaint-rate threshold is documented here.
Yahoo's published expectations for high-volume senders, aligned with Google's bulk-sender rules.
Microsoft's matching bulk-sender rules for Outlook.com, Hotmail, Live.com.
SPF / DKIM / DMARC / BIMI Standards
The internet standards that define email authentication. RFC numbers below are the canonical sources.
Canonical SPF specification including the 10-DNS-lookup limit and qualifier syntax.
DKIM signature standard including selector syntax and signing algorithm specifications.
Canonical DMARC specification including the three policy modes (none, quarantine, reject) and alignment rules.
BIMI experimental specification covering selector format, SVG Tiny PS format requirements, and VMC linkage.
One-click unsubscribe header standard required by Google and Yahoo bulk-sender rules.
Corporate Email Scanners (Defender / Mimecast / Proofpoint)
The three dominant enterprise email security gateways. Each pre-fetches links and images for malware scanning, contaminating click and open tracking.
Microsoft documents Safe Links pre-fetching behaviour; basis for filtering scanner clicks on Microsoft 365 tenants.
Documents Defender's attachment-fetch behaviour which contributes to pre-fetch opens.
Mimecast URL Protect pre-fetches every link on every email for malware scanning.
Proofpoint TAP analyses every URL with sandboxing; pre-fetch behaviour is documented.
Billions of opens and clicks classified in real time, reported by recipient type. At large corporate inboxes behind security gateways, 80-95% of clicks were bots; on Outlook.com and Hotmail about 30%; and about half of consumer email opens have been non-human every year since 2023. Omnivery sells bot detection, so this is a vendor's study.
B2B Engagement & Lead-Response Studies
The benchmark studies for follow-up timing, response rate, and pipeline conversion that Outsolvi cites in its content.
Six companies, 15,000+ web leads and 100,000+ call attempts: the odds of qualifying a lead dropped 21 times when the company called at 30 minutes instead of 5.
Gartner documents the 6-12 stakeholder buying committee thesis Outsolvi references in multi-stakeholder content.
Industry benchmarks for cadence, reply rate, and outbound conversion.
Replicated lead-response-time findings extending the InsideSales work.
Outsolvi Internal Data
Numbers read directly from Outsolvi's tracking engine: how opens are graded and how accuracy gets checked. We don't publish statistics about customers' email.
The engine assigns one of four discrete scores: verified 100 percent, most-likely human 70 percent, possibly human 20 percent, filtered 0 percent. The counting floor is 25 percent, so verified and most-likely update the open count and the other two do not. These are configuration values read from the tracking engine, not estimates.
There is no single accuracy figure, and we would rather say so than invent one. What runs is a weekly precision report: for every classification rule, how often a user confirmed it against how often a user overrode it, over a rolling 30 days. A rule with too little feedback reports nothing rather than a guess.
How we cite, when we update, and what we won't claim
Citation policy. Every quantitative claim on outsolvi.com that comes from outside Outsolvi's own data is attributed to a publisher with a live link. If we can't cite the source, we don't publish the number.
Update cadence. Each long-form content page carries a lastUpdated date that reflects the most recent substantive review. We bump this only on real revisions, not on auto-rebuilds.
What we won't claim. We don't fabricate testimonials, invent customer counts, or cite paid research as independent. We don't publish statistics drawn from customers' email. Where a number comes from Outsolvi itself, it is a setting read from the product, and we say so.
Methodology. The methodology page documents how we compute confidence scores, where benchmarks come from, and how the test environment works.
You checked our sources. Now check our numbers on your own inbox.
Every accuracy claim on this page is testable with the 14-day free trial. Confidence-scored opens from your first tracked send. No credit card.
Nate built Outsolvi after watching every email-tracking tool he had ever used lie to him about opens. Outsolvi runs Tier 1 to 5 confidence scoring on every open, native in Outlook and Gmail, so the number on the dashboard is one a rep can actually act on.
We update these pages when the underlying mechanics change. new mailbox-provider rules, new tracker behavior, new measurement gaps. The dates above are real revisions, not auto-touches.