The best alternative to Geary is Betterbird, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Geary and ten of them are so hopefully you can find a suitable replacement. Other interesting alternatives to Geary are eM Client, EssentialPIM, Airmail and KMail.
Betterbird, a soft fork of Mozilla Thunderbird, improves user experience with advanced features, bug fixes, security patches, and multi-row descriptions similar to Outlook. Compatible with multiple platforms and can be used alongside Thunderbird, sharing the same profile.
eM Client is a full featured e-mail client with a modern and easy to use interface. eM Client also offers calendar, tasks, contacts, notes and chat.
The powerful, full-featured Personal Information Manager for Windows offering Email, Synchronization, Portability, Network support, Android and iOS versions.
Engineered for iOS, macOS, and watchOS, this fast mail client supports multiple account types, custom actions, Smart Inbox filtering, unified inbox, privacy mode, email scheduling, snooze, third-party app integration, flexible personalization, and advanced workflow tools.
KMail is the email component of Kontact, the integrated personal information manager of KDE. Kontact is a personal information manager and groupware software suite for KDE. It supports calendars, contacts, notes, to-do lists, news, and email.
Trojitá, is a fast Qt IMAP e-mail client that respects open standards and facilitates modern technologies. Trojitá values vendor-neutrality that IMAP provides and is committed to be as interoperable as possible.
ProfiMail is a powerful email client for mobile phones. It allows you to read your mail on the go, and send text with attachments directly from your phone. Send photos, recorded sound or simply text messages to friends, from anywhere.
Features:
Koma-Mail is an email client which is comfortable and has very handy functions. It does not need an installation, so that you can run Koma-Mail from your flash drive but, of course, also on your desktop.
Germany
EU
Czechia
Estonia
Italy
Slovakia
One of the best email clients for Windows. Has it all: POP, IMAP, Exchange, Gmail, Outlook and others, Jabber, Google Talk, calendars (Fruux and CalDAV support included) and of course contacts (every major platform plus Fruux and CardDAV). Fast, nice search features, no much bugs...