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Email Client Market Share in November 2021: Mail Privacy Protection (MPP) Adoption Increases


We’re back! It’s that time of the month where we recap the shifts that took place with email client market share last month.

Let’s take a look at what happened in November 2021.

Top email clients

If you’ve been following along, you’ll recall that last month we introduced a new grouping for Apple clients. Apple iPhone (iOS Mail), Apple Mail (macOS Mail), Apple iPad (iPadOS Mail), and Apple Mail Privacy Protection (MPP-impacted opens) will now be listed under “Apple”. To learn why, head over to our blog on email client market share.

And before we dive in, two key things we always like to note: 1) MPP hides device data so we can’t differentiate between iOS, iPadOS, or macOS, and 2) the new OSes also don’t differentiate between MPP and non-MPP in the user agent data it passes.

With that, the top 3 email clients for November 2021 are Apple, Gmail, and Outlook.

Top 10 email clients in November 2021

  1. Apple: 54.2%
  2. Gmail: 31.6%
  3. Outlook: 4.7%
  4. Yahoo Mail: 2.6%
  5. Google Android: 2.2%
  6. 1.1%
  7. Samsung Mail: 0.5%
  8. Windows Live Mail: 0.1%
  9. 0.05%
  10. GMX: 0.04%

Apple’s overall market share went up, from 51.4% to 54.2%. As a result, Gmail went down from 33.7% to 31.6%, although still holding the number two spot. The same goes with Outlook, decreasing from 5.3% to 4.7%.

Want more data and trends? We recently launched our new and improved email client market share site to include Apple’s Mail Privacy Protection (MPP) data, pre- and post-MPP launch.

Let’s take a look at the breakdown for Apple:

  1. Apple Mail Privacy Protection: 26.2%
  2. Apple iPhone (iOS Mail): 20.5%
  3. Apple Mail (macOS Mail): 6.8%
  4. Apple iPad (iPadOS Mail): 0.7%

In October 2021, out of the four Apple clients, Apple iPhone (iOS Mail) was at the top with 27.36% of the share. But this month, Apple Mail Privacy Protection ranked as number one. This isn’t surprising as Apple Mail Privacy Protection (MPP) adoption increases.

To summarize the shifts that took place, Apple Mail Privacy Protection grew its share from 14.35% to 26.16%, causing the other Apple clients to see a drop as well. Apple iPhone (iOS Mail) decreased its share from 27.36% to 20.51%, as did Apple Mail (macOS Mail) from 8.78% to 6.79%, and Apple iPad (iPadOS Mail) from 0.91% to 0.74%.

Opens by environment

MPP launched in September 2021. Though considered early data as adoption is still increasing and normalizing, November 2021 marks the third month of data we’re able to see MPP data with Litmus Email Analytics.

Opens by environment

MPP adoption has increased as expected. Last month we noted how Apple Mail Privacy Protection’s share jumped from 6.6% in September to 14.2% in October (a 115% increase). From October to November, we’re seeing a jump too, from 14.2% to 25.9% (an 82% increase).

  1. Webmail: 37.8%
  2. Apple Mail Privacy Protection: 25.9%
  3. Mobile: 23.7%
  4. Desktop: 11.5%
  5. Other: 1.1%

Something on our minds: How will MPP’s share stack up against the other environments next month, and when will its increase start normalizing?

Most popular mobile opens

As for mobile opens, the top 3 remain the same, as it has for previous months.

Apple iPhone (iOS Mail) did see a small decrease, from 87.9% down to 85.5%. Google Android and Apple iPad (iPad OS Mail) jumped a few percentage points, from 7.3% to 9.3% and 2.9% to 3.1%, respectively.

Most popular mobile opens

  1. Apple iPhone (iOS Mail): 85.5%
  2. Google Android: 9.3%
  3. Apple iPad (iPadOS Mail): 3.1%

Most popular webmail opens

The same story goes with webmail: The top 3 webmail clients are still Gmail, Yahoo Mail, and

Most popular webmail opens

  1. Gmail: 89.2%
  2. Yahoo Mail: 7.4%
  3. 3.2%

Not much movement has happened: Gmail increased slightly from 89.1% to 89.2%, Yahoo Mail decreased slightly from 7.5% to 7.4%, and stayed the same at 3.2%.

Curious why we categorize Gmail as webmail? See how Gmail opens are reported in Email Analytics.

Most popular desktop opens

For desktop clients, the ranking remains the same. Apple Mail (macOS Mail) sits in first with a majority of the share, followed by Outlook in second, and Windows Live Mail in third.

Most popular desktop opens

Apple Mail (macOS Mail) went down a few percentage points, from 61.8% to 58.6%, in line with the decrease we saw when we look at each Apple email client. In contrast, Outlook’s market share expanded from 37.2% to 40.4%, similar to how it increased in October. Windows Live Mail grew slightly from 0.8% to 0.9%. It increased slightly by 0.1% when we looked in October, too.

  1. Apple Mail (macOS Mail): 58.6%
  2. Outlook: 40.4%
  3. Windows Live Mail: 0.9%

Light Mode vs. Dark Mode opens

Light Mode is the most popular setting by a landslide, with roughly 73.1% of all emails being opened in a light mode setting in November. When we checked last month, Light Mode usage increased slightly from 73.7% to 74.4%. However in November it’s back down, to 73.1%. In turn, Dark Mode increased its share slightly, from 25.6% to 26.9%.

Light Mode vs. Dark Mode

  1. Light Mode: 73.1%
  2. Dark Mode: 26.9%

As a reminder: Our Dark Mode data is based only on the Apple Mail app for iOS 13, macOS 13, iOS 14, macOS 14, iPadOS 14, iOS 15, iPadOS 15, and Apple Mail privacy-impacted devices.

Take a look at your audience

Although email client market share provides powerful insights on the industry as a whole, the real value lies with your subscribers.

What will happen next month? Will MPP adoption continue to increase and/or normalize? Stay tuned as we share our findings and continue to track the impact of MPP next month.

Where did we get all this data? Our email client market share stats are pulled from over a billion email opens, anonymously collected and aggregated with Litmus Email Analytics from November 1-30, 2021. It highlights global trends across all industries and verticals. Some email clients may be over- or under-represented, particularly with mobile and webmail. This is due to image blocking or image caching, most notably with Gmail. Still curious? Learn how we get this data.


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