system/libraries/Email.php
/**
		* Get Hostname
		*
		* There are only two legal types of hostname - either a fully
		* qualified domain name (eg: "mail.example.com") or an IP literal
		* (eg: "[1.2.3.4]").
		*
		* @link	https://tools.ietf.org/html/rfc5321#section-2.3.5
		* @link	http://cbl.abuseat.org/namingproblems.html
		* @return	string
		*/
Get Hostname
There are only two legal types of hostname - either a fully
qualified domain name  or an IP literal
.


Get Hostname There are only two legal types of hostname - either a fully qualified domain name or an IP literal .
protected function _get_hostname()
		{
			if (isset($_SERVER['SERVER_NAME']))
			{
				return $_SERVER['SERVER_NAME'];
			}
			return isset($_SERVER['SERVER_ADDR']) ? '['.$_SERVER['SERVER_ADDR'].']' : '[127.0.0.1]';
		}
protected function _get_hostname ( ) { if ( isset ( $ _SERVER [ 'SERVER_NAME' ] ) ) { return $ _SERVER [ 'SERVER_NAME' ] ; } return isset ( $ _SERVER [ 'SERVER_ADDR' ] ) ? '[' . $ _SERVER [ 'SERVER_ADDR' ] . ']' : '[127.0.0.1]' ; }
Get Hostname
 There are only two legal types of hostname - either a fully
 qualified domain name (eg: "mail.example.com") or an IP literal
 (eg: "[1.2.3.4]").
Get Hostname There are only two legal types of hostname - either a fully qualified domain name ( eg : " mail . example . com " ) or an IP literal ( eg : " [ 1 . 2 . 3 . 4 ] " ) .