For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:lrupp/openSUSE_Tumbleweed/home:lrupp.repo
zypper refresh
zypper install spamassassin
For openSUSE Leap 15.1 ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:lrupp/openSUSE_Leap_15.1_ARM/home:lrupp.repo
zypper refresh
zypper install spamassassin
For openSUSE Factory run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:lrupp/openSUSE_Factory/home:lrupp.repo
zypper refresh
zypper install spamassassin
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:lrupp/15.6/home:lrupp.repo
zypper refresh
zypper install spamassassin
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:lrupp/15.5/home:lrupp.repo
zypper refresh
zypper install spamassassin