What Is an Email Client?

Whether reaching out to family and friends, coworkers, or clients, email serves as a reliable form of communication. But managing your email inbox without the right tools can be a frustrating task. Email clients provide a versatile solution to streamline your email experience. In this article, we'll explain what an email client is, compare popular clients like Outlook, Gmail, and Apple Mail, and explain the difference between an email client and an email server.

What is an email client?

An email client, sometimes referred to as a mail user agent (MUA), is a piece of software or web service that lets you send and receive email messages in real time as well as manage your inbox.

It's like your virtual mailbox and work desk, where you can write, organize, sort, and send email messages from one central interface. Clients offer many helpful features, including the ability to add categories to messages, create folders for organization, set up spam filters to block unwanted messages, and add calendar events and contacts.

You've likely used an email client before to communicate, whether you realized it or not. Gmail, Outlook, and Apple Mail are all popular examples.

How do email clients work?

Mail user agents use email protocols as the basis of their functions. They use three primary protocols to send and receive messages: SMTP, POP3, and IMAP.

  • SMTP (Simple Mail Transfer Protocol) is an outgoing email protocol. It works to send messages from your email client to the appropriate mail server. Because it's involved in the sending of messages, it's known as a push protocol.
  • POP3 (Post Office Protocol 3) is an incoming email protocol. It's the predecessor to IMAP; it allows users to download messages from a mail server to their email client. It's known as a pull protocol.
  • IMAP (Internet Message Access Protocol) is the updated incoming email protocol. It also allows users to download messages from a mail server; however, with IMAP, users can retrieve and synchronize their messages with multiple email clients or devices rather than just a single one. This is what separates IMAP from POP3.

Email clients work by using these three protocols to create, send, and deliver messages. Essentially, it involves three steps:

  1. Someone composes an email in their mail user agent. They include the email address of the recipient and hit Send.
  2. The messages goes to an outgoing mail server, or an SMTP server. This server transfers it across the Internet to an incoming mail server, like a POP3 or IMAP server.
  3. The IMAP or POP3 server delivers the message. Then, the recipient can retrieve and read it.
A user accessing their email client on a phone

Email client examples

There are many mail client options out there, as either standalone software, web applications, or mobile apps. They have similar features, differing mainly in aesthetics and user interface experience. The one you choose will depend on personal preferences, including your operating system and feature preferences.

Outlook

Outlook, a Microsoft product, is one of the most widely used email clients around the world. It comes with the Microsoft 365 Office suite, which also provides popular Microsoft tools like PowerPoint, Word, Excel, and Teams. It is accessible via standalone software, web application, and mobile device. Outlook is favored by businesses and organizations because it offers a comprehensive set of features tailored for organization and productivity.

With Outlook, you can manage multiple email accounts, easily schedule appointments with a built in calendar, access messages with keyboard shortcuts, and manage contacts all from the app. Additionally, Outlook provides many plug-ins that work seamlessly with other software apps like Zoom, Slack, Asana, Salesforce, ClickUp, and more.

Because of its user-friendly and familiar interface and robust security features, Outlook is a preferred choice for businesses and organizations.

Windows Mail

Mail, previously known as Windows Mail and Windows Live Mail, is a Microsoft email web client. As of 2024, it is currently being phased out with Windows 11, set to be completely replaced by Outlook for Windows.

Apple Mail

With around 60% of market share among email clients, Apple Mail is the most popular client for personal use by a wide margin. It comes pre-installed as the default client on macOS and iOS devices, and offers smooth integration with the Apple product ecosystem with a sleek and intuitive design that Apple users have come to expect.

Additionally, it supports a wide range of email providers. For example, you can use Apple Mail with a Gmail.

Gmail

Gmail is Google's email client and Outlook and Apple Mail's main email competitor. When Gmail was introduced, it shook up the email landscape with its intuitive interface and powerful integration features. Offering impressive storage space, automatic spam filtering, and integration with popular Google products like Drive, Google Docs, and more, all accessible with one Gmail account. Due to these features, Gmail has quickly become one of the most popular email clients for personal use.

Yahoo Mail

Yahoo Mail, like Yahoo itself, has been around a long time in the Internet and email landscape. It provides a satisfactory alternative to Outlook, Apple Mail, and Gmail. However, it is the clear fourth place client in terms of popularity.

Thunderbird

Thunderbird is a standalone, open-source email client known for its flexibility and customization options. Developed by Mozilla, it can be installed on various operating systems, including Windows, macOS, and Linux.

People like Thunderbird due to its extensive support for extensions, allowing individuals to customize its functionality according to their preferences. Moreover, known for its robust security and privacy features, Thunderbird is particularly cherished by privacy-conscious and tech-savvy users seeking tailored customization to meet their needs.

Think of Thunderbird as the Android phone of email clients, offering flexibility and adaptability. On the other hand, clients like Gmail and Apple Mail are more like the iPhone, in as far as they provide more features preconfigured.

Why use an email client?

Regardless of which client you use, all of them have similar benefits and features that will help you manage your inbox. Consider the benefits of using an email client for the next time you need to send a message online.

Privacy and security

Email clients prioritize security and privacy, offering email encryption, two factor authentication, and spam filtering. Additionally, some clients offer local storage without the need of Internet connection, which gives users more control over their data without having to use cloud-based storage.

Management and organization

Email clients let users access all their inbound and outbound messages from one interface. Additionally, some clients let you create categories and folders for sorting and prioritizing messages. This is particularly helpful in professional settings when you may be managing multiple projects or client interactions.

Additionally, with features like search and conversation threads, finding and managing email correspondence is easier than ever.

Customization

Some clients, particularly Outlook and Thunderbird, offer many customization options and third party plugins which let users tailor their experience to meet their specific needs.

Offline access

Standalone email clients like Outlook and Thunderbird offer offline access to previously seen messages and drafts. This is very helpful for certain situations where internet access is unavailable when traveling.

Email clients vs. email servers

Mail user agents and email servers both play an important role in email communication, but they server distinct functions.

As discussed, email clients are software applications that let you send, receive, and manage email messages. They serve as the interface and offer various features for composing emails, managing the inbox, and integrating with third party apps. These clients are located on the user's device.

Email servers, on the other hand, are computer systems responsible for receiving, delivering, and storing data from email messages. They transmit and route messages between sender and recipient mailboxes. Examples include the Microsoft Exchange Server, Postfix, and Sendmail. They are hosted on dedicated hardware systems or cloud-based infrastructure and serve as the backbone of all email communication.

Email clients provide interfaces for managing emails, with features to help you write, access, and organize all your messages. Popular clients include Apple Mail, Outlook, Gmail, Yahoo, and Thunderbird. Research the features of your client to make sure you're getting the most functionality to streamline your digital messaging experience.

Frequently asked questions

How does an email client communicate with email servers?

Email clients communicate with email servers by using email protocols, like SMTP and IMAP. The email client uses the SMTP protocol to create an authentication extension. Then, the server can validate the sender and receive the incoming mail.

Is Gmail an email client?

Yes, Gmail is an email client. However, it's also an email service.

Is Outlook an email client?

Yes, Outlook is an email client.