Originally Posted by arun5002
You have not mention the distro of operating system for installation of postfix mail server .I could prefer you to follow the link if ur planning to install postfix on ubuntu distro of operating system.
If it is Red Hat 5 or CentOS 5. by defualt sendmail run.
Important Note; After installing postfix ,use the alternative command to switch from sendmail to postfix within the system.
Do google for how to configure postfix.