This article is from the Mac communications FAQ, by Bruce L Grubb BruceG6069@aol.com with numerous contributions by others.
Yes there is; it is called comp.binaries.mac. But due to the nature
of Usenet it has become impractical to post today's larger MacOS
programs. In any case this is the *only* proper mac newsgroup to post
a MacOS program binary.
Any as explained in section [2.2] any MacOS program intended for
comp.binaries.mac must be in BinHex 4.0 format following the
step described in section [3.5].
As far downloading what few programs do appear on comp.binaries.mac
use a NewsWatcher baced newsreader and simply select extract binaries.
This will do the tedious task of joining up a multipart binary for you.
Otherwise there is not much reason to bother with comp.binaries.mac.