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What Are the Most Used Email Service Providers?

There are several email service providers one can use for business and personal use. Read this guide to learn about the most popular email providers.

When you’re sending an email to hundreds or thousands of people, it’s essential to ensure that email looks good for everybody. Understanding why clients render email differently and what you can do to make sure your emails look good across several clients is crucial for email marketing.

It’s important to focus on the most popular email service providers so that your emails look the same across different email clients. According to the numbers, Gmail and Outlook are some of the best email service providers to focus on.

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If you want to know more about designing your emails to accommodate the most popular email providers, here’s a list of the biggest names.


Gmail by Google is one of the most popular web clients for email because it’s free and easy to use. In fact, Gmail accounted for 36.5% of email opens globally in 2021. Gmail supports 105 languages and also offers paid plans for businesses of all sizes. The plan you choose determines the storage, support options, and features that are available to you.

One of the best parts of Gmail is that it’s simple and works with virtually any device. Gmail is compatible with the most popular web browsers, plus it’s available on Windows and Apple computers and iOS and Android mobile devices. Gmail can also be installed on ChromeOS and other Linux-based operating systems.


Outlook is an email client offered by Microsoft as part of the Microsoft Office package. In addition to this paid version of Outlook, there’s a free web version, which was previously known as Hotmail. With Outlook, users have access to a clean interface with great features, such as deleted email recovery, add-on support, and automatic email organization.

Just like Gmail, Outlook works with several operating systems and devices, so it can be used across several devices and platforms. Linux operating systems are the only exception since there’s no official Outlook client for Linux. Outlook is user-friendly and can be integrated with many different apps, making it a popular choice for business and individual use.

When it comes to email deliverability and widespread compatibility, Outlook and Gmail are two of the most popular options.


ProtonMail is different from Gmail and Outlook because it provides enhanced security. ProtonMail uses end-to-end encryption to ensure users get complete privacy with every email they send. Because the company is based out of Switzerland, they abide by Swiss privacy laws.

In addition to offering added security, ProtonMail also offers features like Proton Calendar and Proton Drive, making it a solid choice compared to some of the other popular options. Plus, ProtonMail is easy to use, so there’s no steep learning curve to worry about. While ProtonMail is popular, it’s not quite as ubiquitous as Gmail and Outlook.

AOL Mail

There was a time when AOL was the biggest name on the internet. While times have changed and AOL is now a division of Verizon Communications, AOL Mail is still one of the more popular email clients. AOL Mail allows you to link to other email accounts, such as Outlook and Gmail, and provides an unlimited mailbox size. Virus and spam protection is built right in, too.

One thing to keep in mind with AOL Mail accounts is that they’re deactivated after 90 days of inactivity and deleted after 180 days of inactivity. You might want to check your mailing list to make sure you’re not emailing deactivated AOL accounts.

Yahoo! Mail

Launched in 1997 and currently available in 27 languages, Yahoo! Mail is one of the oldest email clients on the web. While Yahoo! Mail began as a web client more than two decades ago, it has grown to the point where mobile apps exist for it. Yahoo email address domains include “” and “” Yahoo! Mail is great for personal emails, especially for people who use other Yahoo services.

While Yahoo! Mail isn’t quite as popular as Outlook and Gmail, the email provider has 225 million active users. So, using Inbox Preview to verify whether an email looks good for Yahoo! Mail is important for your marketing campaigns.


Zoho is an Indian technology company known for its suite of office applications, which is aptly called Zoho Office Suite. While Gmail and Outlook are still popular choices for many businesses, Zoho is becoming increasingly popular—with 15 million users worldwide—which can be due to its clean layout, excellent security, and affordable premium plans for both personal and business use.

Depending on your plan, Zoho offers domain aliases, email hosting, offline access, email recall, attachments as large as 1 GB, and more. If you prefer feature-filled email service providers, Zoho is a solid option.

iCloud mail

iCloud has become increasingly popular as iPhones and iOS operating systems are big players in the tech world. As long as you have an account with Apple and an Apple device, you can connect to iCloud mail using your Gmail, Hotmail, Yahoo! Mail, or AOL Mail address. Even though iCloud is compatible with several other email providers, it still renders email differently.

While iCloud mail is a popular option because it comes preinstalled on iPhones and other Apple devices, many users may choose to download Gmail or other third-party email services. That being said, it’s still important to design your emails for iCloud Mail.


GMX is one of the email service providers you may have never heard of. There are two different versions of GMX email: one for German users and one for English, French, and Spanish users. The version you choose determines the features available with the free version of GMX mail.

With GMX mail, you’ll have access to features like virus and spam protection, drag-and-drop for files, and file-sharing capabilities with attachment sizes as large as 50 MB. GMX mail also supports SMTP, POP3, and IMAP4.

While designing your emails with GMX mail in mind is a good idea, remember that it isn’t quite as popular because it heavily relies on the use of pop-up ads.

Although it is not as well-known as Gmail or Outlook,'s extensive features cannot be overlooked. is one of the most robust free email service providers available today for both personal and professional email accounts.

With, users are not limited to one domain extension for their email address. Instead, users have the option to choose from more than 200 domain extensions for the perfect fit for their business and brand.

While is free of charge, allowing anyone to create an email address of their own, there is also a premium version of available. The premium version of eliminates ads, provides additional storage, and offers access to premium services.

Just a few of the tools that are made available to all users who register an email account with include:

  • Online Office: Instantly gain access to a digital word processor and spreadsheet tools to manage files that are important to you directly in your email.
  • Organizer: Use a robust real-time calendar to manage contacts, schedule appointments, and even set reminders. You can also opt to connect and synchronize any other calendars you are using to manage your business or email account(s).
  • MailCheck: MailCheck is an integrated feature from that provides notifications whenever any of your email accounts receive new mail in real-time.
  • Alias email addresses: In addition to registering a free standard email address with, permits users to create up to 10 email addresses within a single account.
  • Storage: All users of are permitted 65GB of storage for no cost.
  • Filters: Sort emails with premade templates and filters or create your own to streamline the management of your incoming emails.

A few of the security features that are provided for all accounts (including free email addresses) from include:

  • Antivirus: Maintain peace of mind whenever you are using your email knowing that an antivirus is active and protecting your inbox at all times.
  • Spam filter: The use of a spam filter goes well beyond putting a stop to annoying emails. Spam filters can also significantly reduce viruses and malware from making it to your inbox.
  • 2FA: Two-factor authentication is also available and can be enabled to provide an additional layer of security to your email account when using

Whether you are searching for an email service provider that will allow you to create your own email design templates or if you prefer safety and security when it comes to your email, is a solid choice.

Email service providers: FAQs

What is the most widely used email service?

According to Statista, Gmail is the most popular email client in today’s world, with more than 1.5 billion active users globally.

If you’re going to focus on designing your emails for one email provider, Gmail is a good place to start.

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The native email app that’s preloaded onto Apple iPhones is the second most commonly used email service. This is because every iPhone user who logs in with an Apple ID has their email connected to Apple Mail. Outlook is also a prevalent email client for both personal and business use. Knowing this can help make your emails look great in all inboxes since you can tailor your email designs to the specific service.

How to transfer emails from one service provider to another?

In order to transfer emails between email services or email providers, you’ll need to sign up for an email account with the provider you want to switch to. Once you’ve signed up for an account, you’ll need to repoint your email-related DNS records. After you’ve got that settled, you’ll need to set up IMAP and SMTP and check if your email address is working.

Transferring emails from one service provider can be difficult on your own, so consider using a tool that does it for you or requesting professional help.

Which is the best free email service provider?

If you’re looking for the best business email service without spending money, looking at the most popular email providers is a good place to start. Gmail, Outlook, and ProtonMail are all great choices for secure, feature-rich business email services.

Keep in mind that every business has different needs, so it’s important to compare features and find an email client that offers everything you need. Features like large attachment sizes, built-in storage, and tools for editing documents can help out business owners.

Does Hotmail still exist?

If you have been around since the expansion of the internet to the general public, you are likely well aware of the existence of Hotmail. However, you may be wondering if Hotmail still exists. While Hotmail in itself does not exist as a brand or as an organization any longer, it has been rebranded as one of the most popular email platforms on the planet: Outlook. Outlook today is what Hotmail once strived to be as far back as the mid-1990s.

Although Hotmail originally launched in 1996, its last official update came in 2005, when it could no longer compete with the rise of Gmail, Google's own email provider. In 2012, Microsoft officially launched Outlook, which allowed those who had a registered Hotmail account the option of upgrading their own accounts and transferring their data to Outlook.

While the original Hotmail platform no longer exists, Microsoft's Outlook is now a leading email service provider, competing directly with Google's Gmail for the top spot. Those who are interested can register a free email account with Microsoft Outlook within just a few minutes.

What security features should I look for in an email service provider?

Choosing the best email service providers can feel overwhelming with so many diverse platforms and solutions available online. However, if security is your top concern, there are a few features to look for in your next email service provider, such as:

  • 2FA: Two-factor authentication is becoming increasingly commonplace with most digital platforms today. Using two-factor authentication provides an additional layer of security to all email addresses used on a particular platform, minimizing the risk of leaving your email address vulnerable.
  • Antivirus: When you are choosing an email service provider, it is recommended to find a provider that offers antivirus protection to all of its users, including those who have a free email account.
  • Spam handling: Do you want to minimize the risk of receiving potentially harmful files, such as malware and viruses? If so, finding an email service provider with robust spam handling, filters, and protection is a must. With the rise of spam, it is imperative to use email service providers that understand the risk of allowing emails with harmful files to bypass any filters that are in place.
  • Uptime: An email service provider with a 100% uptime record and a 99-100% guarantee rate is essential if you are searching for an email service provider that protects its users.
  • Syncing/security: If you are looking to find an email service provider that offers the ability to synchronize all of your external email accounts, you should do so only with a platform you can trust. Always read reviews and testimonials of those who have used platforms for security purposes before choosing the free email service providers that are right for you.

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Make your emails look good across different service providers

There are several email clients on the market, but it’s important to know which clients are popular so you can design an email that looks great and is responsive. Some of the best email service providers include Gmail, Outlook, and ProtonMail. As long as you’re designing for the most popular clients, your emails should be accessible and readable. A/B testing is also an important part of ensuring your emails look good across multiple clients.

With Mailchimp, getting the most out of your inbox is easy. Mailchimp makes email marketing and automation straightforward for businesses, and you can use Inbox Preview to see how your email will look with different email service providers. Try Mailchimp today to see how your emails will look on AOL, Gmail, Outlook, Yahoo!, and more.

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