Apps similar to Zimbra Desktop include Thunderbird, which is free and open source. Other options are Microsoft Outlook, Falkon, Evolution and Mailspring. Email Clients like Zimbra Desktop are a crowded field, with more than 50 alternatives for Windows, Linux, Mac, Android and iPhone.
Scribe is a small portable email client with an intergrated contact database and calendar. It supports all the major internet mail protocols and uses international standards where possible. Scribe doesn't required installing or uninstalled and can be used from a removable...
Tunnel is a simplistic, minimalist web browser based on the principle that even if you don't use the internet very often, using Tunnel is probably still not a very good idea. It is one of the premier browsers for downloading other browsers, continuing the longlasting legacy...
Built from the ground up for speed. Flectar Mail delivers native performance, instant startup, and as little as 20 MB of RAM.
Spain
EU
Orbit Communicator is a client server application that's designed to be deployed locally on your desktop machine. It currently provides an integrated email / calendaring experience based on external IMAP mail sources.
United Kingdom
Sup is a console-based email client for people with a lot of email. It supports tagging, very fast full-text search, automatic contact- list management, custom code insertion via a hook system, and more.
Columba is an email client written in Java, featuring a user-friendly graphical interface with wizards and internalionalization support. Its a powerful mail management tool with features to enhance your productivity and communication.
FixBrowser is a truly lightweight web browser created from scratch. It intentionally doesn't support JavaScript to make things faster and much less resource intensive. Instead it contains an updated set of scripts that fix and improve various websites.
Feng Office is a commercial Open Source web based solution aimed to enhance collaboration and productivity. It integrates information such as mails, documents, notes, favourites, events and task. This online office is aimed at small business, which use it for project management...
The most powerful platform for email productivity in a beautiful native app — on desktop and mobile.
United States
Eudora started in 1988, at the University of Illinois because the internet was a growing and burgeoning place, but email was not really established on the desktop computers that people were using at the time.
An enterprise application server that integrates information into a single workspace, integrates also a full mail server
India
Experimental terminal mail client aiming for configurability and extensibility with sane defaults.
Uruguay
