Changed a few strstr to strpos for consistency w performance guidelines and to mirror EE2.
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index 8014bd2..09d1b8f 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -1865,7 +1865,7 @@
 		elseif ($cip)		$this->_IP = $cip;
 		elseif ($fip)		$this->_IP = $fip;
 
-		if (strstr($this->_IP, ','))
+		if (strpos($this->_IP, ',') !== FALSE)
 		{
 			$x = explode(',', $this->_IP);
 			$this->_IP = end($x);