Claws Mail Alternatives

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

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

VoIPstudio is an award-winning VoIP system that offers businesses of all sizes a scalable communication solution. It’s inexpensive, easy-to-use, offers a full suite of PBX features, and is fully integrated for CRM.

Try for free paid Free Trial $4.99 / Monthly (User)

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

Open Source

Apps/Evolution - GNOME Wiki!

Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues

Open Source

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

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

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

The Power Email App for busy professionals, like you.

Geary is an email application built for GNOME 3.

Secure email with absolutely no compromises. Get your free encrypted email account today.

freemium €5.0 / Monthly (user - 5 GB)

Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.

freemium

Open source, privacy friendly email app

Open Source