For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:kukuk/openSUSE_Tumbleweed/home:kukuk.repo
zypper refresh
zypper install systemd-status-mail
For openSUSE Factory ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:kukuk/openSUSE_Factory_ARM/home:kukuk.repo
zypper refresh
zypper install systemd-status-mail
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:kukuk/15.6/home:kukuk.repo
zypper refresh
zypper install systemd-status-mail