Thunderbird (Email and Calendar)
I used Thunderbird way back in the day when it and Firefox split off of Mozilla/Seamonkey, later switching to KMail on my Linux desktop (since it ran a lot faster) and then just using Gmail through the web. Recently I’ve been trying to reduce my dependence on Google, and since Thunderbird was familiar, cross-platform, and had just updated its UI (codename: “Supernova”), I figured I’d give it another shot.
It’s worked out great! More stable and capable than Microsoft Mail and News on Windows, fewer system complications than KMail on Linux (especially when running it on a non-KDE desktop), more capable than Geary on Linux, and more respectful of my privacy than the new Outlook. (That said, Geary is great for low-resource systems.)
The new UI is a lot cleaner than it used to be, and most setup can be done without digging into the advanced settings. But the advanced settings are still there in case you need them.
Easy to set up multiple email accounts including Gmail and Outlook.com, can fully manage an IMAP account, and can even move messages between accounts (which is really helpful when migrating).
Also works well with Nextcloud calendar and contacts. Old directions will say you need an extension, but CalDAV and CardDAV support are built in now. The hardest part was looking up the right URL on my Nextcloud server! Note: Syncing will be faster with an app-specific password for Thunderbird.
I haven’t used it much on macOS, since the lighter-weight Apple Mail is good enough for most purposes, but it’s my preferred mail application on Windows and Linux these days.
For email troubleshooting purposes: Thunderbird does not alter the raw source of messages when it saves them. This turned out to be crucial when debugging a 7bit vs quoted-printable issue because I could see what was actually being sent!
Also: For some reason, Fedora’s packaged Thunderbird launcher doesn’t auto-detect whether you’re running on Wayland or Xorg like Firefox does, so it runs in XWayland. You can install the
thunderbird-wayland RPM package to get a launcher that runs it directly on Wayland.
Finally: Thunderbird, like Firefox and other Mozilla projects, is free/libre open-source sofware. You can audit the code, modify your own version, suggest bugfixes, or use another project that’s based on it. (Note to self: Try out Betterbird. Hat tip to Susan Calvin for the suggestion.)