Inky 

Inky is more than just an email client for your Mac. Besides helping you read and send emails to your recipients, this program is also capable of preventing phishing attacks and provides you with a wide range of email sorting options and a powerful search utility.

After you install the application on your Mac, you might want to check if there are any updates available. The download URL for this app doesn't give you access to the latest version of the program. So, make sure you update the app if you want to work with the newest version of the utility and get access to its latest improvements.

Inky supports Office 365, Microsoft Exchange, Gmail, and many other IMAP services. Simply log in to your email account and you can immediately start sending messages to your contacts, reading and sorting emails, etc. Unfortunately, you might need to wait a while for the application to load the login screen.

The most important advantage is the fact that it automatically encrypts all email data using AES-256-GCM encryption. Furthermore, it keeps your inboxes in sync with your email provider.

Briefly, it's worth installing this utility on your Mac only if you're the type of user who sends and receives multiple emails on a daily basis. The application provides you with multiple helpful features and is efficient. Also, the developer brings you 2 more editions of this app that gives you access to extra features but with a cost.