Apple MPP Impact Estimator
Estimates how many of your reported opens are Apple MPP pre-fetches rather than real human reads. Based on Litmus 58% global Apple Mail market share and the MPP enabled-by-default rate.
Takes your list size, estimated Apple Mail % on the list (default 58% per Litmus 2026), and MPP-enabled rate (default 50% conservative), then estimates the expected MPP pre-fetch volume. Compares this to your reported open count to estimate the inflation.
When your reported open rate seems suspiciously high (e.g., 70%+ on cold lists) and you want to know how much of that is real human reads vs MPP pre-fetches.
How to use it
- 1Enter your list sizeTotal prospects you've sent the campaign to.
- 2Adjust the Apple Mail percentageDefault 58% per Litmus 2026. Tech/SaaS audiences often skew higher (65-75%).
- 3Read the inflation estimateThe tool shows expected MPP pre-fetch volume vs your reported opens. Subtract to get real human reads.
Common use cases
- •Building a board-deck slide on 'why our open rates look inflated'
- •Sanity-checking a sequence's reported performance before celebrating
- •Estimating which segments (Apple-heavy vs not) need different open-rate goals
FAQ
Where do the default percentages come from?+
Litmus puts Apple Mail at roughly 58% global email-client market share in early 2026. The MPP-enabled rate (50% conservative) reflects that the iOS 15 first-launch prompt's recommended option is 'Protect Mail activity' and most users accept the default. The actual MPP-enabled rate on real lists is often higher than 50%; conservative estimate.
Does the calculator work for cold lists or warm pipeline?+
Both. Cold lists trend higher MPP density (tech/SaaS-heavy targeting). Warm B2B pipelines vary; mid-market typically tracks the 58% baseline.
What can I do to track the non-MPP audience accurately?+
Confidence-scoring at the open level. Outsolvi tiers every open Tier 1 (high-confidence human) through Tier 5 (proxy/scanner). MPP pre-fetches land at Tier 4-5 and get filtered from your real-engagement metrics automatically.
Should I just stop tracking opens entirely?+
No. opens are still a signal, just a noisier one. Stop using raw open count as a hot-lead trigger; start using a confidence-weighted combination of opens + clicks + replies. The signal-to-noise ratio recovers.
Why this tool matters
Apple Mail Privacy Protection is the most consequential change to email tracking infrastructure of the last decade and the one most B2B sales teams still measure their pipelines as if it didn't happen. Since iOS 15 shipped in 2021, Apple's servers pre-fetch every tracking pixel on every email delivered to an Apple Mail user with MPP enabled, regardless of whether the human ever opens the message. From the sender's tracker's perspective, those emails look opened within minutes of send.
The reach is enormous. Litmus' 2024 Client Share Report puts Apple Mail at ~58% of global email opens. Of those, roughly half have MPP enabled (Apple's default-on first-launch prompt does most of the work here). That's a 25-35 percentage-point lift in raw open rate that has nothing to do with engagement and everything to do with Apple's privacy infrastructure.
This estimator is the honest math. You enter your list size and the rough composition (% Apple Mail users on your list, usually 40-70% for B2B prospect lists), and it tells you how many of your reported opens are likely proxy pre-fetches versus actual human reads. Most teams running through it see 30-50% of their open count vanish. The remaining number is the one you can actually act on.
Keep going
Articles, glossary entries, and other tools on the same topic.
You ran the math. Outsolvi makes it real.
Calculators tell you what the number should be. Outsolvi tells you what your number actually is. confidence-scored opens, real reply sentiment, live deal-level signal across Outlook and Gmail. From $7/user/mo yearly, 14-day free trial.
See it on your own inboxNate 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.