Man pages matching name postmaster in section 1:

postmaster.1.zh_CN	debian 10 / manpages-zh
postmaster.1.zh_TW	debian 10 / manpages-zh
postmaster.1.zh_CN	debian 11 / manpages-zh
postmaster.1.zh_TW	debian 11 / manpages-zh
postmaster.1.zh_CN	debian 12 / manpages-zh
postmaster.1.zh_TW	debian 12 / manpages-zh