Mail for Mac might be a great service for the majority of Apple users, but some require a more feature-rich service to use on a daily basis. Below are the top Mac email clients in 2020 that support in-app integration, multiple account setup, quick replies, and much more.

To help you pick out the best email client for your use, we reviewed the best ones below.
Table of Contents
Airmail
Airmail is arguably one of the best mac email clients of all time, optimized for outstanding speed, reliability, and stability. Not to mention, it is currently one of the most fluid apps in terms of matching the built-in Mail app for macOS.
Airmail features one of the most visually appealing designs out there today. It can support email providers like Gmail, iCloud, Yahoo, Outlook, AOL, and more.
It comes with a ton of features such as gesture support, quick replies, filter management, and unified inbox. Also, it supports apps within apps such as Calendar, Reminders, Evernote, Fantastical, and more to have a more integrated feel. For coders out there, Airmail includes AppleScript support and other code-related programs to help personalize your mail experience.
Airmail now offers a dark mode, and for the MacBook Pro users, it additionally offers Touch Bar support. You can customize the Touch Bar to make working more easygoing. Not just that, you can even choose from a variety of plugins to add support for Read Receipts, SMIME, or GPG encryption.
Spark
Spark is one of the most unique mailboxes in its approach towards group email organization and message interaction. This includes one of its greatest features: being able to view a full context of past emails on the person you are currently talking to.
Spark offers a modern design, which is quick and natural. Collaborating has never been more simple, it truly is a personal experience. One of the defining features of Spark is the Smart Inbox. Smart Inbox lets you promptly see what's important in your inbox and clean up the rest. All new emails are smartly categorized into Personal, Notifications, and Newsletters. Further, you can also schedule emails to be sent when your recipient is most likely to read them. The scheduling works even if your device is turned off.
You can easily integrate Spark into your workflow and take productivity to the next level. It supports Dropbox, Box, iCloud Drive, and more. For business emails, you can quickly swipe to choose the right signature for the occasion. Spark also lets you Quick Reply with just a tap. You can love, like, or acknowledge emails in one single tap.
Why is Spark so good? It takes a terrible mess in your inbox and replaces it with a beautiful, threaded message design. Can't recommend enough.
Postbox
Postbox is all about managing your emails for heavy users - they try to make it as easy and efficient as possible. To do this, Postbox as a four part interface design called the Focus Pane which separates and labels emails based on attributes such as reminders, subscriptions, attachments, etc.
Other features include favorite contact optimization and topics that break larger emails into chunks for easier viewing. If you browse around the email client you’ll also notice account groups, tabs, and a favorites bar.
Also, check out the quick replies feature Postbox sports, this allows you to customize a set of basic templates in case you send out frequent responses. Postbox is available for macOS and Windows.
Newton Mail
Newton Mail (formerly CloudMagic) is available for use on the Mac desktop after it got its start as an email client on the iPhone and Android. Having been around for so long, it is no wonder that this client performs so well. It features a very clean and pleasant interface.
Newton Mail also ranks high with functionality as it can support Gmail, Outlook, Yahoo, Office 365, Exchange, and more. Though the price may be on the higher end, it is worth it for all of the helpful features. Users can enjoy a unified inbox, filters, keyboard shortcuts, standard set of aliases, HTML support, and more.
Conclusion
Email clients serve more than just the single purpose of replacing lower-grade built-in applications. They offer incredible features to give a better overall performance and help you manage your time along with email customization.
Among the best mac email clients we listed, we think the best one you could possibly use today is Airmail and Spark. Both of them are simple fluid apps, containing more high-quality features, and allowing for interaction among some of the best mac apps within the email itself. Not to mention, they are easily one of the most popular email clients to date.
I'd agree with you about Airmail if "search" & "smart folders" worked correctly for a start! I've used it for about a year. I need a better solution ... it just cannot be relied upon in a busy, email intensive scenario.