For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:weberho:UNSTABLE:tine20/openSUSE_Tumbleweed/home:weberho:UNSTABLE:tine20.repo
zypper refresh
zypper install tine20-felamimail
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:weberho:UNSTABLE:tine20/15.5/home:weberho:UNSTABLE:tine20.repo
zypper refresh
zypper install tine20-felamimail
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:weberho:UNSTABLE:tine20/15.4/home:weberho:UNSTABLE:tine20.repo
zypper refresh
zypper install tine20-felamimail
For 15.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:weberho:UNSTABLE:tine20/15.3/home:weberho:UNSTABLE:tine20.repo
zypper refresh
zypper install tine20-felamimail