FILTER_VALIDATE_EMAIL not working - php

Question

I certainly must be missing something here. For some reason filter_var is not working. I'm trying to validate an email from $_POST, and it returns false even with valid emails. But, when I hardcode an email, it works fine. What's wrong?
Here's my php code:
function redirect() { //redirecting to home page function. Used in one of the lectures.
$host = $_SERVER["HTTP_HOST"];
$path = rtrim(dirname($_SERVER["PHP_SELF"]), "/\\");
header("Location: http://$host$path/index.php");
exit;
}
try
{
$dbh = new PDO($db, $dbuser, $dbpassword);
}
catch (PDOException $e)
{
echo "Connection failure: " . $e->getmessage();
}
if (!isset($_POST['email']) || !isset($_POST['password1']) || !isset($_POST['password2'])) {
redirect();
}
$password1 = htmlspecialchars($_POST['password1']);
$email = htmlspecialchars($_POST['email']);
$password2 = htmlspecialchars($_POST['password2']);
//preg_match('/.+#.+\./', $email) == FALSE
if ($email = "") {
print "email not there";
} elseif (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
print "not real email";
} elseif (strlen($password1) < 6) {
print("password too small");
} elseif (!(preg_match('/[A-Za-z].*[0-9]|[0-9].*[A-Za-z]/', $password1))) {
print "numbers and letters plz";
} elseif ($password1 != $password2) {
print "passwords not same";
//redirect();
}

Answer 1

Change the first email check:
if ($email == "") {
print "email not there";
}
It is getting the value " instead of checking for it.