dovecot from spins:invis:rootpack project
Select Your Operating System
Add repository and install manually
For openSUSE Leap 42.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/spins:invis:rootpack/openSUSE_Leap_42.3/spins:invis:rootpack.repo zypper refresh zypper install dovecot