For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:crameleon:mailman/openSUSE_Tumbleweed/home:crameleon:mailman.repo
zypper refresh
zypper install python-mailman
For openSUSE Factory zSystems run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:crameleon:mailman/openSUSE_Factory_zSystems/home:crameleon:mailman.repo
zypper refresh
zypper install python-mailman
For openSUSE Factory PowerPC run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:crameleon:mailman/openSUSE_Factory_PowerPC/home:crameleon:mailman.repo
zypper refresh
zypper install python-mailman
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:crameleon:mailman/15.5/home:crameleon:mailman.repo
zypper refresh
zypper install python-mailman
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:crameleon:mailman/15.4/home:crameleon:mailman.repo
zypper refresh
zypper install python-mailman