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What’s the deal with all the different email clients out there? You’ve got Gmail, Apple Mail, Yahoo Mail!, Outlook, Thunderbird, and heaps more. And each of these email clients plays by their own rules. That means they can each render your emails in different ways which have been wreaking havoc on marketers for years. 

With so many different email clients out there, you have to consider how your emails will look across a multitude of inboxes and devices.

This guide to email clients will provide you an overview of the most popular email clients so you can set your emails up for success in every client and device.

Chapter 1

How email clients effect your email marketing

With the plethora of email clients out there marketers really have to plan for everything when creating their emails. And we’ve been lamenting the issue for years with outcries to Microsoft, Gmail and more asking for some relief.

Thankfully, modern email design tools like Campaign Monitor take much of the guesswork out of it and provide a lot of insight before we ever have to push send.

So what are the most popular email clients out there and how do we know which ones our subscribers are using?

Top 10 most popular email clients

The top ten email clients to date are as follows:

Email Client Market Share

Source: Email Client Market Share:

Fine print: This leaderboard of the most popular webmail, desktop, and mobile email clients is compiled from data collected worldwide by Litmus Email Analytics, and displays up-to-date figures for the top 10 email clients. Since determining the client in which an email is opened requires images to be displayed, the data for some email clients and mobile devices might be over- or under-represented due to automatic image blocking.

Which email clients are your subscribers using?

Each time a subscriber opens an email sent with Campaign Monitor, we keep track of which email client they’re using. You can see this in the Reporting section of your account under Email Client Usage.

Here’s an example:

Track Email Clients Your Email Subscribers are Using

In the example above, understanding that the majority of subscribers are viewing the email in Gmail and on iPhones might help you decide the best length for your email subject lines because 41 characters (portrait view on an iPhone) to 70 characters for Gmail would be best for these subscribers.

Chapter 4

Testing email clients using Campaign Monitor

At Campaign Monitor, we want to help marketers conquer send fear; that sometimes debilitating fear that takes over just before we send an email because we fear something won’t work.

To ensure your email will look awesome in every email client and on every device, we have  the Inbox Preview feature.

Campaign Monitor - Test Your Email Campaign

Inbox Preview will show you exactly how your email will look in 30 of the most popular web, desktop, and mobile email clients.

Inbox Preview will also run a complete spam filter and firewall test and instead of just scanning your content for “spammy words”, Inbox Preview will pass your email through real spam filters and firewalls, then give you full details on the outcome. Then you can rest assured that your email will fabulous in inboxes everywhere.

Chapter 5

Wrap up

Now that you know the most popular email clients, you can plan, optimize, and test your emails for success before you push send. Then, regardless of which email clients your subscribers use, your emails will be successful.

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