and if the sums do not match, the message cannot be installed.
PackMan messages can be installed by using the Install option under the
PackMan options by entering an 'X' at the 'Enter message option' prompt.
Installing a message will replace the data on disk, but a BACK-UP message
can be created before the installation takes place. Automatic BACK-UP is
prompted for before installation is allowed.
If a message is secured, a security check takes place during the
installation. The message is checked against previously calculated sums,