First, run the following command:

perl Makefile.PL

If this command says that some prerequisite modules are not present,
you need to install these modules; each required one should
be shipped with pgpenvelope, and found in the "modules" directory.
If not, fetch them from CPAN at http://www.cpan.org/

Next, run the following commands:

make
make test
make install

Finally, consult "man pgpenvelope" for help on how setup Pine's filters
and procmail configurations to run pgpenvelope.
