http://software.virtualmin.com/gpl/debian/dists/virtualmin-etch/main/binary-i386/
http://software.virtualmin.com/gpl/debian/dists/virtualmin-etch/main/binary-i386/procmail-wrapper_1.0-2_i386.deb
install the package with a simple: sudo dpkg-i-wrapper_1.0 procmail-2_i386.deb
Then you should check the permissions of the Permit procmail-wrapper which can be found in / usr / bin:
rwsr-xr-x 1 root root 2.9K 11/28/2006 10:08 procmail-wrapper
in fact it should already be ok after installation. In particular, if s does not appear in user permissions you will have problems.
Finally we verify that postfix uses our wrapper and procmail directly:
sudo nano / etc / postfix / main.cf
ensure that there is the following directive:
mailbox_command = / usr / bin / procmail-wrapper-o-a $ DOMAIN-d $ LOGNAME