Before you compile the program, you need to create users and groups that will be expected to be in place when the install script executes. Add the users and groups with the following commands: groupadd courier && useradd -c 'Courier Mail Server' -d /dev/null -g courier -s /bin/false courier You also need to create a bin user. If you already have a user named bin this step can be safely ignored. useradd -c 'bin' -d /dev/null -g bin -u 1 bin This creates a /var/run/courier directory where all the Courier MTA pid files will exist. This will allow courierfilter.pid to be created. Without the courierfilter running the Courier MTA will not work. Issue the following commands to create /var/run/courier: mkdir /var/run/courier && chown courier:courier /var/run/courier Install courier by running the following commands: ./configure --prefix=/usr --libexecdir=/usr/lib/courier \ --datadir=/usr/share/courier --sysconfdir=/etc/courier \ --localstatedir=/var/lib/courier --with-piddir=/var/run/courier \ --disable-root-check --with-mailuser=courier --with-mailgroup=courier \ --with-paranoid-smtpext --disable-autorenamesent \ --enable-workarounds-for-imap-client-bugs && make && make install && make install-configure