Sendmail start-up error

Problem:
451 4.0.0 /etc/mail/sendmail.cf: line 91: fileclass: cannot open '/etc/mail/local-host-names': World writable directory
451 4.0.0 /etc/mail/sendmail.cf: line 588: fileclass: cannot open '/etc/mail/trusted-users': World writable directory

This means that somewhere between the path of "/" to "/etc/mail/" is a World writable directory or a 777. In my case it was "/etc".

Change the permission to 755:
[root@linux]# chmod 0755 /etc

Start sendmail:
[root@linux]# service sendmail start