Hi Jananee_iNautix,
On the Email alert settings Settings page, you can define the Mail server settings (the mail host, security type, username, password, and so on) and the Email format (link hostname, email sender name, email subject header, and inline results format).
In other words, you specify the Message Transfer Agent (MTA) or mail server your Splunk server will use to send out alert emails. In *nix this is per default localhost, if it is not localhost enter the hostname and if needed some credential to authenticate to be able to send emails.
hope this helps ...
cheers, MuS
