Zimbra Desktop Alternatives

Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

Mailbird is the best email client for Windows 7, 8 and 10

eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.

freemium

Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.

multi-channel inbox service for collaborative teams

Airmail is a lightweight and lightning fast mail client for Mac.

Spike is a content marketing platform that drives content recommendations to your target audience, helping to amplify your message and connect with customers.

Mailspring is a mail client for Mac, Windows and Linux.

Shift is the ultimate email client for managing Mail, Calendar, Drive, Slack, Asana, Jira, Evernote, and all your other favourite apps

freemium

The Power Email App for busy professionals, like you.

K-9 is an opensource email client making it easy to chew through large volumes of email.

Amazon WorkMail is a secure, managed business email and calendar service.

Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client (mailer, MUA).