groupadd exim useradd -g exim exim : Create the group and user exim which will run the the exim daemon. sed -e 's/^BIN_DIR.*$/BIN_DIRECTORY=\/usr\/sbin/' src/EDITME | \ sed -e 's/^CONF.*$/CONFIGURE_FILE=\/etc\/exim.conf/' | \ sed -e 's/^EXIM_USER.*$/EXIM_USER=exim/' | \ sed -e 's/^EXIM_MONITOR/#EXIM_MONITOR/' > Local/Makefile : Many of exim's configuration options are compiled in. Here, we specify the minimum set of options, BIN_DIRECTORY, CONFIGURE_FILE and EXIM_USER. We also defer building the exim monitor program, which requires X windows support, by commenting out the EXIM_MONITOR line in the Makefile. ln -s /usr/sbin/exim /usr/sbin/sendmail : Create a link to sendmail for applications which need it. exim will accept most Sendmail command line options.