Apple MPP Impact Estimator
Estimates how many of your reported opens are Apple MPP pre-fetches rather than real human reads, from your list size and your guess at how many recipients read on Apple Mail.
An estimate from the numbers you entered, not a measurement. It treats every Apple Mail reader with Mail Privacy Protection on as someone who didn't read, so the real rate is likely somewhat higher. Totals alone can't tell you which opens were people; that takes looking at each open.
You ran the numbers. Now see your real ones.
A calculator works from the figures you type in. Outsolvi measures them on the email you actually send, and grades every open so Apple Mail pre-fetches and security scanners don't inflate the count. Outlook and Gmail, from $7/user/mo billed yearly, 14-day free trial.
See it on your own inboxTakes your list size, estimated Apple Mail % on the list (starting guess 58%), and MPP-enabled rate (starting guess 50%), 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 percentageThe default is a starting guess of 58%. Raise it for audiences heavy on Apple devices, like tech and SaaS buyers, and lower it for lists that mostly read mail in Outlook.
- 3Read the inflation estimateThe tool shows expected MPP pre-fetch volume vs your reported opens, and what's left after subtracting it. Treat that as a rough lower bound, not a count of real human reads: some Apple Mail readers do read, and totals can't show which ones.
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?+
They're starting guesses, not measurements. Apple Mail accounted for 62 percent of the opens Litmus measured in July 2026, across consumer and business mail, and Litmus says studies put Mail Privacy Protection at 55 to 60 percent of all opens. The 58 percent Apple default sits a little under Litmus's all-mail figure, and the 50 percent MPP default is deliberately low, since Apple Mail's first-launch prompt recommends 'Protect Mail activity'. If you know your own list, use your numbers.
Does the calculator work for cold lists or warm pipeline?+
Both. What changes is the mix: a list heavy on tech and SaaS buyers usually has more Apple Mail readers, and a list of large enterprises usually has more security scanners. Set the Apple Mail share to match your list.
What can I do to track the non-MPP audience accurately?+
Grade each open instead of counting pixel loads. Outsolvi labels every open, from Verified and Most-likely human down to Apple Mail, Machine preview and Scanner. Apple Mail pre-fetches stay out of your open count.
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. Apple Mail accounted for 62 percent of the opens Litmus measured in July 2026, and Litmus says studies put Mail Privacy Protection at 55 to 60 percent of all opens. Apple Mail's first-launch prompt recommends turning it on, which does most of the work. Every one of those opens is Apple's servers fetching the pixel, not a person reading.
This estimator is the honest math. You enter your list size and your best guess at how many of your recipients read on Apple Mail, and it tells you how many of your reported opens are likely proxy pre-fetches versus actual human reads. The remaining number is the one you can actually act on.
Keep going
Articles, glossary entries, and other tools on the same topic.
Nate built Outsolvi after watching every email-tracking tool he had ever used lie to him about opens. Outsolvi grades every open as a person or a machine, 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.