To be able to use this package, you'll need to put in in a subdirectory of the 'core' package.

To be able to use the script that handles returned mails, you'll have to do
the following:
- edit config.php to suit your needs
- run 'make mailer' (from this directory)
- move the contents of './mailer/' to '/etc/smrsh/'
- change group: 'chgrp smrsh /etc/smrsh/${EVENTNAME}*'
- set guid: 'chmod g+s /etc/smrsh/${EVENTNAME}*'
- add a line to aliases file:
  ${EVENTNAME}_return:  "|/etc/smrsh/${EVENTNAME}.php error"
- create a new aliases database: 'newaliases'
If your system was properly configured beforehand, this should be all you need
to do.