Welcome (back) to our monthly recap of email client market share changes and trends that happened in the previous month. Compared to our annual email client market share blog post, this series looks at month-to-month data. And September has some curious sightings because of a not-so-small thing called Mail Privacy Protection (MPP) that Apple rolled out to its Mail app on iOS 15 and iPadOS 15 on September 20. What did we see? Well, you're going to have to keep reading to find out. Top 10 Email Clients Overall The top 3 email clients are still Apple iPhone (iOS Mail), Gmail and Apple Mail (macOS Mail) before and after MPP. To be clearer, before MPP is data from
September 1-19 and after MPP is data from September 20-30. Top 10 email clients in September 2021 So, has the MPP changed anything? Yes, after MPP, Apple iPhone was finally dethroned, losing 13.4% of its share compared to before MPP. Gmail is now ranked as the most popular email client overall. That being said, a decent chunk of the iPhone's share was taken by what we call "Apple Mail Privacy" - all openings impacted by MPP - which account for 6.6% of the email client market share. (currently ranked #4). If we assume they all come from the iPhone E-Commerce Photo Editing Service (since the iPad share is so small and macOS Monterey with MPP hasn't been released yet), then Apple's iPhone would still be ranked #1 . Two key things to note here: 1) MPP hides device data so we can't tell the difference between iOS, iPadOS, or macOS, and 2) newer operating systems also don't tell the difference between MPP and non-MPP in user agent data. past. This means that everything opens from the Mail app on iOS 15 and iPadOS 15, whether MPP is enabled or not, looks the same to us . I know. We didn't expect that. On the plus side, we expect most people who upgrade their Apple OS to have MPP enabled, so our data is probably very close to reality anyway.