<?php
$rows = Array("email@gmail.com","test@gmail.com","tester@gmail.com","vin@gmail.com");
$contacts = Array
(
"test@gmail.com" => "test@gmail.com",
"ram@gmail.com" => "Ram",
"vin@gmail.com" => "Vinay",
"man_test@yahoo.com" => "Manoj",
"homan@rediffmail.com" => "Homan"
);
$contacts = array_diff_key(array_map('trim', $contacts), array_map('trim', array_flip($rows)));
print_r($contacts);