Linux: Creating sendmail.cf using m4

After modifying the sendmail.mc on a linux mail server your need to recreate the sendmail.cf file.

m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf

provided that /etc/mail/sendmail.mc has the following lines at the top:
dnl ### Include default Sendmail cf file
include(`/usr/share/sendmail-cf/m4/cf.m4')dnl

other wise you need to include it on the command line:

m4 /usr/share/sendmail-cf/m4/cf.m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf

Now if everything goes without error issue the following to restart sendmail:

/etc/init.d/sendmail restart