This guide will lead you through setup of the SMTP relay function of sendmail on Solaris & Linux.

Typical installation of Solaris and Red Hat Linux (RHEL3) will include the components needed to make sendmail work.

If the RPM's for sendmail are not installed for your Linux distro, install them::

rpm -ivh sendmail-<version>.rpm
rpm -ivh sendmail-cf-<version>.rpm
rpm -ivh m4-<version>.rpm

You may be able to find the needed RPM's at http://linux.[Directory-Info.com.net/install]

If the sendmail configuration file (sendmail.cf) doesn't exit, create it:
NOTE: The configuration file on RHAS 2.1 is /etc/sendmail.cf; on Solaris and RHEL3 it is /etc/mail/sendmail.cf.

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

Edit the sendmail configuration file with SMTP relay info:

vi /etc/mail/sendmail.cf

Make sure sendmail is in the system startup (Red Hat Linux):

chkconfig --list sendmail
sendmail        0:off   1:off   2:on    3:on    4:on    5:on    6:off

Add to system startup if necessary (Red Hat Linux):

chkconfig --add sendmail
chkconfig sendmail on

Start sendmail:

/etc/init.d/sendmail stop
/etc/init.d/sendmail start

Test it (use mail for Linux, mailx for Solaris):

mail -s"Test" john_g_johnson@[Directory-Info.com].com
This is the emergency broadcast system.

Here is some documentation from Red Hat about "Mail Transfer Agents":