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.
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's MPP is the single largest contaminator of open-rate accuracy in 2026. The primary sources below document the mechanism, scope, and impact.
Apple confirms MPP pre-loads remote content on Apple-controlled servers before recipient action.
Litmus tracks email client market share across major providers; Apple Mail dominant share is the basis for MPP impact calculations.
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.
B2B Engagement & Lead-Response Studies
The benchmark studies for follow-up timing, response rate, and pipeline conversion that Outsolvi cites in its content.
Tracked 15,000+ leads; established the 5-minute response window thesis (21x qualification odds vs 30+ min).
Gartner documents the 6-12 stakeholder buying committee thesis Outsolvi references in multi-stakeholder content.
Industry benchmarks for cadence cadence, reply rate, and outbound conversion.
Replicated lead-response-time findings extending the InsideSales work.
Outsolvi Internal Data
Claims sourced from Outsolvi's own production data. Each is reported with sample sizes and time windows where applicable.
95-98% agreement with human-rated classifications on the held-out B2B test set. False-positive rate (Tier 1 graded when actually a machine) <2%. False-negative rate (Tier 4-5 graded when actually a human) <5%.
Across ~50M opens analysed in H1 2026, 60-70% of all open events fire within 10 seconds of send (machine pre-fetch signature). Net result: reported open rates run 2-3x inflated on typical B2B lists.
Same-day follow-up on Tier 1 multi-opens lifts reply rate 30-50% vs equivalent untimed touches.
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. Where Outsolvi data is the source we say so explicitly, with sample sizes and time windows listed.
Methodology. The methodology page documents how we compute confidence scores, where benchmarks come from, and how the test environment works.
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.