/usr/share/sendmail/cf/ostype/ is in sendmail-cf 8.15.2-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/sendmail/cf/ostype/a-ux.m4
/usr/share/sendmail/cf/ostype/aix3.m4
/usr/share/sendmail/cf/ostype/aix4.m4
/usr/share/sendmail/cf/ostype/aix5.m4
/usr/share/sendmail/cf/ostype/altos.m4
/usr/share/sendmail/cf/ostype/amdahl-uts.m4
/usr/share/sendmail/cf/ostype/bsd4.3.m4
/usr/share/sendmail/cf/ostype/bsd4.4.m4
/usr/share/sendmail/cf/ostype/bsdi.m4
/usr/share/sendmail/cf/ostype/bsdi1.0.m4
/usr/share/sendmail/cf/ostype/bsdi2.0.m4
/usr/share/sendmail/cf/ostype/darwin.m4
/usr/share/sendmail/cf/ostype/debian.m4
/usr/share/sendmail/cf/ostype/dgux.m4
/usr/share/sendmail/cf/ostype/domainos.m4
/usr/share/sendmail/cf/ostype/dragonfly.m4
/usr/share/sendmail/cf/ostype/dynix3.2.m4
/usr/share/sendmail/cf/ostype/freebsd4.m4
/usr/share/sendmail/cf/ostype/freebsd5.m4
/usr/share/sendmail/cf/ostype/freebsd6.m4
/usr/share/sendmail/cf/ostype/gnu.m4
/usr/share/sendmail/cf/ostype/hpux10.m4
/usr/share/sendmail/cf/ostype/hpux11.m4
/usr/share/sendmail/cf/ostype/hpux9.m4
/usr/share/sendmail/cf/ostype/irix4.m4
/usr/share/sendmail/cf/ostype/irix5.m4
/usr/share/sendmail/cf/ostype/irix6.m4
/usr/share/sendmail/cf/ostype/isc4.1.m4
/usr/share/sendmail/cf/ostype/linux.m4
/usr/share/sendmail/cf/ostype/maxion.m4
/usr/share/sendmail/cf/ostype/mklinux.m4
/usr/share/sendmail/cf/ostype/mpeix.m4
/usr/share/sendmail/cf/ostype/nextstep.m4
/usr/share/sendmail/cf/ostype/openbsd.m4
/usr/share/sendmail/cf/ostype/osf1.m4
/usr/share/sendmail/cf/ostype/powerux.m4
/usr/share/sendmail/cf/ostype/ptx2.m4
/usr/share/sendmail/cf/ostype/qnx.m4
/usr/share/sendmail/cf/ostype/riscos4.5.m4
/usr/share/sendmail/cf/ostype/sco-uw-2.1.m4
/usr/share/sendmail/cf/ostype/sco3.2.m4
/usr/share/sendmail/cf/ostype/sinix.m4
/usr/share/sendmail/cf/ostype/solaris11.m4
/usr/share/sendmail/cf/ostype/solaris2.m4
/usr/share/sendmail/cf/ostype/solaris2.ml.m4
/usr/share/sendmail/cf/ostype/solaris2.pre5.m4
/usr/share/sendmail/cf/ostype/solaris8.m4
/usr/share/sendmail/cf/ostype/sunos3.5.m4
/usr/share/sendmail/cf/ostype/sunos4.1.m4
/usr/share/sendmail/cf/ostype/svr4.m4
/usr/share/sendmail/cf/ostype/ultrix4.m4
/usr/share/sendmail/cf/ostype/unicos.m4
/usr/share/sendmail/cf/ostype/unicosmk.m4
/usr/share/sendmail/cf/ostype/unicosmp.m4
/usr/share/sendmail/cf/ostype/unixware7.m4
/usr/share/sendmail/cf/ostype/unknown.m4
/usr/share/sendmail/cf/ostype/uxpds.m4