The documentation for maildrop has been installed in
${PREFIX}/share/doc/maildrop.

You should also read the pkg/SECURITY file now, as it has
some important information regarding the setuid/setgid
bits that some of the binaries that have been installed 
may need for correct operation.

There are currently NO setuid/gid bits enabled, but if you
use maildrop in certain capacities, these will need to be
set to allow maildrop to function correctly.