MozillaThunderbird from home:Herbster0815:mozilla project
Select Your Operating System
Add repository and install manually
For openSUSE Leap 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Herbster0815:mozilla/openSUSE_Leap_15.6/home:Herbster0815:mozilla.repo zypper refresh zypper install MozillaThunderbird