PHP obfuscated or hide part of the email address

I wrote my own function for one of the project to display first 3 characters and last characters before the @. In between the first and last 3 characters, put in 3 star (*).

So, this is how it looks like

/**
* hide part of the email address
* @param string data, email address
* @return string obfuscated email address
*/
public static function process_obfuscated_email($data)
{
	//obfuscate email address
	$expl_email = explode("@", $data);
	$email_name = $expl_email['0'];
	$length = strlen($email_name);
	
	if($length >=9)
	{
		$first_3 = substr($email_name, 0, 3);
		$last_3 = substr($email_name, -3);
		$obfuscated_email = $first_3."***".$last_3."@".$expl_email['1'];
	}
	if($length < 9)
	{
		$av_sub = $length - 6;
		if( $av_sub > 0 )
		{
			$first_3 = substr($email_name, 0, 3);
			$last = substr($email_name, -$av_sub);
			$obfuscated_email = $first_3."***".$last."@".$expl_email['1'];
		}
		elseif( $av_sub == 0 )
		{
			$first_3 = substr($email_name, 0, 2);
			$last = substr($email_name, -2);
			$obfuscated_email = $first_3."***".$last."@".$expl_email['1'];
		}
		else
		{
			$first = substr($email_name, 0, 1);
			$last = substr($email_name, -1);
			$obfuscated_email = $first."***".$last."@".$expl_email['1'];
		}
	}
	return $obfuscated_email;
}

By Keenlio, January 17, 2014