Description:
------------
Email with multiple period in a row fail validation when they are working email.  
With gmail you can add periods into any email address and it will still deliver.  
I use this to filter out messages.  example@gmail.com is the same as 
exam.....ple@gmail.com  or exam.ple@gmail.com or exam.p.l.e@gmail.com.

With one period or if there is a letter or number between period the 
FILTER_VALIDATE_EMAIL works just fine but if more than one period it fails. 

Test script:
---------------
<?php
$email_a = 'exmple@gmail.com';
$email_b = 'exm.a.p.le@gmail.com';
$email_c = 'exa......mple@gmail.com';

if (filter_var($email_a, FILTER_VALIDATE_EMAIL)) {
    echo "This ($email_a) email address is considered valid.\n";
} else {
    echo "$email_a failed\n";
}

if (filter_var($email_b, FILTER_VALIDATE_EMAIL)) {
    echo "This ($email_b) email address is considered valid.\n";
} else {
    echo "$email_b failed\n";
}

if (filter_var($email_c, FILTER_VALIDATE_EMAIL)) {
    echo "This ($email_c) email address is considered valid.\n";
} else {
    echo "$email_c failed\n";
}

Expected result:
----------------
This (exmple@gmail.com) email address is considered valid.
This (exm.a.p.le@gmail.com) email address is considered valid.
This (exa......mple@gmail.com) email address is considered valid.

Actual result:
--------------
This (exmple@gmail.com) email address is considered valid.
This (exm.a.p.le@gmail.com) email address is considered valid.
exa......mple@gmail.com failed