I employ PHP 5.3.10. Here is the code:
<?php
$email = "test@example.c";
if (filter_var($email, FILTER_VALIDATE_EMAIL))
echo "Email: ".$email." correct";
else
echo "email not correct";
?>
"Email: test@example.c correct," it responds.
According to this list: http://data.iana.org/TLD/tlds-alpha-by-domain.txt, I'm not aware of any top level domains (TLDs) that are only one character in length.
Therefore, is the FILTER VALIDATE EMAIL filter functioning properly or not?