Fossamail is an email client for Microsoft Windows and Linux systems that is based on code of the popular Thunderbird email client.
Update: FossaMail has been discontinued due to a lack of time, funds and users.
I prefer desktop mail programs over cloud-based web mail services for a variety of reasons. Mozilla Thunderbird has been my preferred desktop email client for many years.
I consider it one of the best clients in this regard even though Mozilla more or less decided to put it on life support. While most see this as a bad thing, it does not necessarily have to be, considering that there is not much that you can add to an email client in terms of functionality once you have the basics covered.
A couple of things could be better however. A dedicated 64-bit version for Windows is missing for instance.
This is similar to how Firefox is treated on Windows, but with the difference that a 64-bit Nightly version of the operating system is provided.
The author of Pale Moon, an optimized version of Firefox that is available for 64-bit versions of Windows, maintains the email client FossaMail as well which is based on Thunderbird and offers similar traits as Pale Moon.
The most noticeable difference is that FossaMail is offered as a 32-bit and 64-bit version for Windows just like Pale Moon is offered in the same way.
The program uses its own profile folder, located under %APPDATA%\FossaMail by default so that it won't interfere with Thunderbird profiles that may be available on the system as well. Since it does not interfere with Thunderbird, it is easy to test FossaMail on the system to find out if it works better than Thunderbird.
It is however possible to move an existing profile into the FossaMail profile folder to integrate it into the mail client right away.
You won't notice many differences when it comes to interface or functionality. FossaMail is based on Thunderbird ESR releases and the author will follow those so that you can update the mail client shortly after those versions of Thunderbird are updated by Mozilla.
A special 64-bit version of Lightning is being made available on the official website as well which you can download and install in FossaMail to use the calendar add-on that Mozilla integrated into Thunderbird some time ago.
Most extensions for Thunderbird -- and plugins -- will work just like in the mail client. Since both clients use the same core it is unlikely that you will run into any issues in this regard.
Plugins on the other hand will only work if the right architecture is supported, but since plugins are not really used much or even at all in email clients, that should not be much of an issue as well.
As far as requirements are concerned, FossaMail requires at least Windows Vista and a processor with SSE2 support.
There is no
Linux or Max version available of the email client.
So why would you want to use FossaMail? The most obvious reason is 64-bit support for Windows which means that it can address more memory and perform 64-bit operations. So, if you want that, FossaMail is definitely an option.
Add-on and plugin support may be an issue depending on API usage of said programs.
Thunderbird users will have no issues using the email program as it uses the same interface which makes switching to FossaMail a breeze.