Hello and welcome to LinuxQuestions,
Have you looked at Google first? A quick search turns up the following link
. If you only want to send out mails like you mention then all you need is an MTA like Postfix (a lot easier then sendmail). Since you mention Red Hat Enterprise Linux, I imagine you're paying for your subscription, so you have access to the repositories. Install Postfix using your package manager instead of downloading and installing manually. Last but not least, Red Hat is not free, so you can always put your money to work and call Red Hat Support.