I'm very new to elementary (and to Linux in general; i like especially elementary OS.) In the AppCenter I can't find the current version of Thunderbird or Evolution. Will it come later and is this a usual delay? Thank you.
Elementary OS is an excellent choice and version 5.1 Hera supports Flatpak which gives you an alternative source for applications. It just so happens that the latest version (at the time I wrote this :)) of Thunderbird (68.3.0) and Evolution (3.34.2) are available on Flathub.
In order to get support for Flatpak apps in the AppCenter you will need to sideload your first application as outlined below:
- Open flathub.org in your browser
- Search for either Thunderbird or Evolution using the search bar at the top of the page
- Click on the application in the search results
- Click on the "Install" button which will download a file ending in .flatpakref (e.g. org.gnome.Evolution.flatpakref)
- Once the file is downloaded navigate to your Downloads directory using the Files application
- Click on the newly downloaded file and you will be warned that this is not an Elementary OS curated application but you will be given the option to install it anyway
- Check the "I understand" box and click on "Install Anyway"
- Once the application is installed you will find it in your Application s menu and the flathub.org repo will be added to the App Center allowing you to install any other Flatpak applications on Flathub using the App Center
NOTE: Applications that exist in both the standard AppCenter repo and the Flathub repo will have a dropdown under the name allowing you to choose which version you want to install. In your case you will want to choose the flathub version.