I have previously recommended that Big Sur users upgrade to a test release of MailMate since it fixes various Big Sur related issues. Some Big Sur users are also the lucky owners of an M1-based computer (Apple Silicon) and they should know that the latest test releases of MailMate are also so-called universal releases which support both M1-based and Intel-based machines using native code.
Here is a direct link to the latest recommended release for Big Sur. It is also possible to upgrade by holding down ⌥ when clicking “Check Now” in the Software Update preferences pane. At the time of writing, the release number should be r5798.
The caveats mentioned in the previous blog post are still true, but macOS users are upgrading faster than ever before. More than half of current MailMate users are now on Big Sur and it’s a bit strange recommending a test release for a majority of MailMate users. I’ll be working hard on making it a public release, but there are still a lot of issues left to fix and a lot of changes to document.
Note that the test releases require macOS 10.12 or later (the current public release requires 10.10 or later).