Configuring RelayHost in Sendmail

Let's assume the Mail RelayHost name is "mailserver.domain.com".

Edit the following file /etc/mail/sendmail.mc

define(`SMART_HOST', `mailserver.domain.com')

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

# Restart the Sendmail service

   /etc/init.d/sendmail restart