As the software is now reasonably mature, Procmail is usually available for installation on most Linux distributions and can be installed by using the package manager. This is the recommended way to install Procmail. If it is not available via a package manager in your Linux distribution, it can also be installed from the source code.
For Fedora users, the simple way to install Procmail if it isn't already installed is to use the yum
command as follows:
yum install procmail
For Debian-based users you could use the following command:
apt-get install procmail
This will ensure that the binary of Procmail is correctly installed on your system and you can then decide how you want it to integrate into your Postfix system.
Procmail may be obtained from a number of sources but the official distribution is maintained and available from www.procmail.org. There you will find links to a number of mirror services...