Best K-9 Mail Alternatives & Competitors in 2023

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)

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

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

freemium €5.0 / Monthly (user - 5 GB)

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

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

Open source, privacy friendly email app

Open Source

Gmail is available across all your devices Android, iOS, and desktop devices. Sort, collaborate or call a friend without leaving your inbox.

BlueMail is an email management app for Android, iOS, and Windows.

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

freemium

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

Open Source

Apps/Evolution - GNOME Wiki!