If your team is celebrating a 70% open rate on cold outreach, check how much of it is machines.
Email open tracking has been quietly broken since September 2021. That is when Apple shipped Mail Privacy Protection in iOS 15, and the industry's go-to engagement metric became unreliable overnight. Most tools have not adjusted. Most Account Executives are still reading a number padded with machine opens, then making follow-up decisions on top of it.
This piece walks through the three forces that distort open rates in 2026, a worked example of how far off your number can be, what to ask your tracking tool, and the metric AEs should track instead.
What Apple Mail Privacy Protection actually does
Apple Mail Privacy Protection launched with iOS 15 in September 2021 and is now standard across iOS 15+, iPadOS 15+, and macOS Monterey and later. The first time a user opens the Mail app after upgrading, Apple prompts them to choose whether to enable MPP, and the prompt's recommended option is "Protect Mail activity." Litmus says studies now put MPP at roughly 55 to 60 percent of all email opens.
When MPP is on, two things happen behind the scenes. First, Apple pre-loads every piece of remote content in the email, including your tracking pixel, on Apple's relay servers before the user opens the email. Second, the IP address reported to the sender is Apple's relay, not the recipient's actual IP. The geolocation is meaningless. The open timestamp is meaningless. The user might never open the email at all.
Apple Mail accounted for 62% of the opens Litmus measured in July 2026, across all the senders it tracks. Your list will differ: lists that read mostly on iPhones and Macs, as many tech, SaaS and agency lists do, will see more MPP opens, and lists that read mostly in Outlook at work will see fewer.
Apple describes the behavior on its Mail Privacy Protection page, and introduced it with iOS 15 in 2021. There is no technical workaround. MPP-distorted opens cannot be detected by counting pixel loads alone. They can only be detected by analyzing the pattern of the load: instant timestamp, Apple-attributable IP block, no follow-up click activity. Outsolvi labels these Apple Mail and leaves them out of the count unless the person also clicks or replies. Trackers that count every pixel load count them as full opens.
Gmail's image proxy: a real open with Google's details
In December 2013, Gmail started loading every image in an email through Google's servers on the googleusercontent.com domain. The original justification was privacy and security. For tracking it changed two things.
First, the request comes from Google, not the reader. Gmail still fetches the pixel when the message is viewed, so the open is usually real, but the IP address, location and device your tracker records are Google's.
Second, one view can reach your tracker as several fetches in quick succession, and each can register as a separate open if the tool doesn't group them.
Outsolvi counts the first Gmail proxy fetch as a most-likely-human open and groups any fetch within ten minutes of an earlier one into it. A tool that counts every fetch overstates Gmail opens; a tool that throws proxy fetches away misses real readers. The Gmail image proxy write-up has the evidence.
Corporate email scanners: the third (and stealthiest) source
This one is invisible until you go looking for it. Most enterprise email gets routed through a security gateway before delivery. Mimecast, Proofpoint, Microsoft Defender for Office 365, and Cisco Secure Email all pre-fetch every link and every image in every email to scan for malware, phishing, and known-bad infrastructure.
When a security gateway pre-fetches your tracking pixel, your tool records an open. When it pre-fetches every link, your tool records clicks. None of this is the human. The human has not even seen the email yet.
The signature is distinctive once you know to look for it. Scanners fire a burst of pixel and link requests within seconds, often from one IP block, and they click every link, not just one, which no real person does. Omnivery found that at large corporate domains, 80 to 95 percent of clicks came from these scanners. Outsolvi marks this traffic as a scanner and leaves it out of the count.
Tools differ here, and most don't show you how they decided. Before you trust a tracker's open and click counts on enterprise accounts, ask how it handles gateway scanners and whether you can see the reason on each event.
The math: how far off your number can be
You can't know your real open rate without grading each open, but you can see how easily the raw number runs away from it. Take a made-up list and state the assumptions out loud:
- Half your recipients read on Apple devices with Mail Privacy Protection on.
- One in five sits behind a corporate gateway that opens everything to scan it.
- Everyone else registers an open only when they actually read.
Now say 30% of people genuinely read your email. The Apple half registers an open whether they read or not: 50 points. The gateway group registers one too: another 20 points. The remaining 30% of the list registers an open only when someone reads, and 30% of them do: 9 points.
Your dashboard shows 79%. The real figure is 30%.
Change the assumptions and the gap moves a lot, which is the point. On a list that reads mostly in Outlook at small companies, it may be modest. On a list of iPhone readers at large enterprises, most of your opens can be machines. That's why Outsolvi grades every open instead of counting pixel loads: the number you act on should be people, not the mix of devices and gateways on your list.
This matters because AEs make follow-up decisions on the wrong signal. They follow up the prospects who "opened three times" when those three opens were Mimecast's scanner running once per minute. They skip the prospect who looks dead but actually read the email on a desktop without MPP and is sitting on it. The cadence misses the buyer.
How most tools handle it (or do not)
Setting Outsolvi aside for a moment, here is how the major tools sit on filtering as of May 2026.
Mailtrack (Mailsuite). Built for simple open tracking, with a free Outlook add-in that tracks opens only, without links or a dashboard. It's the cheapest option here; check how it treats machine opens before you rely on its counts. See how Outsolvi compares to Mailtrack for a side-by-side.
Yesware. Says it filters opens from proxies and security scanners, and tracks links and attachments too. It doesn't document a per-open grade or reason you can check. Pricing is $15 to $65 per user per month billed yearly. The Outsolvi vs Yesware comparison covers the differences.
Mixmax. Gmail-first, with Outlook support that skips classic Outlook for Windows. Paid plans run $29 to $89 per user per month billed yearly. Check how it treats machine opens before you rely on its counts. The Outsolvi vs Mixmax breakdown covers what is included at each tier.
HubSpot Sales Hub. Enterprise-grade scanner and MPP detection, the most accurate of the big-name tools by a clear margin. Filters are not exposed to the user, but the underlying open count is closer to reality. The catch is price: $90 to $150 per user per month for the tracking-included tiers. If you are paying enterprise prices, the filtering is largely solved. Most AEs are not paying enterprise prices.
Outsolvi. Grades every open as verified (the person replied), most likely human, possibly human, or a machine (Apple Mail, link preview, scanner). Only verified and most likely human opens count toward your open rate. Repeat Gmail-proxy fetches within 10 minutes are grouped into one open, and scanner bursts are labelled. The point is not that the rules are more complex (they are not), it is that the grade and a plain-English reason are shown to the rep so they can act on it. Individual is $7 a month billed yearly or $12 monthly, for one seat; Pro is $20 per user a month billed yearly.
What AEs should track instead
Open rate is the wrong North Star metric for outbound in 2026. There are cleaner signals, and the sales community has been writing about this for two years.
Reply rate weighted by reply latency. Josh Braun, who writes on LinkedIn about modern outbound, returns to this point repeatedly: replies are signal, opens are noise. The variation worth adding is when the reply lands. A reply within four hours signals a buyer in the active evaluation window. A reply after seven days signals a cold lead who is being polite. The follow-up plan for each is different.
Click depth on high-intent pages. A click on your pricing page or your comparison-vs-Yesware page is worth ten opens. A click on your homepage is worth one. Outsolvi records every click and labels scanner clicks, so the clicks you act on were made by people.
Multi-touch engagement patterns. Florin Tatulea, who has written extensively about data-driven outbound, makes the case that single signals are unreliable and combinations are predictive. An open followed by a click followed by a forward, all within 48 hours, is a higher-confidence buying signal than any single metric in isolation. Outsolvi doesn't compute an engagement score; its hot-lead rule is a simpler version of the same idea.
Forwards and replies-not-to-you. When a prospect forwards your email to a colleague, the colleague is now part of the buying committee. When they hit reply-all and bring in a procurement contact, the deal has entered the next stage. These events are visible to a tracking tool that watches the thread, not just the open.
The hot-lead threshold. Five counted opens plus two clicks, both on the same email, with no time window. This is the trigger for Outsolvi's hot-lead flag and the trigger an AE should use for "drop everything and call this person now." Sarah Brazier and Will Aitken have both written about same-day follow-up on intent signals as the highest-leverage move in outbound. Outsolvi gives you a clean threshold to act on.
How to audit your current tracking today
Pull last quarter's data from your current tool. Look at the open count for any thread that did not result in a reply. If the open count is high and the prospect never clicked a link, be suspicious: repeated opens with no click are often machines. Now look at the threads that did convert. You'll usually see a few opens, a click on a page that matters, and a reply soon after.
If your tool does not let you see the open pattern, just the count, you are flying with one instrument. That is the gap Outsolvi was built to close. Try it free for 14 days, no credit card, and run the same campaign through both tools for a week. You'll see the gap between reported and real opens on your own list, which is the only version of that number worth trusting.
The metric that will move your number this quarter is not opens. It is reply rate inside the active evaluation window, and the tool that surfaces it cleanly is the one worth running.