How do I use a variable in DELETE FROM subscribe WHERE statement?

How do I use a variable in DELETE FROM subscribe WHERE statement?

$sql = "INSERT INTO subscribe (email) VALUES ('$email')"; works.

$sql = DELETE FROM subscribe WHERE email = $email;  errors out.

I tried SET @email = $email;

Then $sql = DELETE FROM subscribe WHERE email = @email;

Parse error: syntax error, unexpected '@' in /home/birdbr7/public_html/scripts/welp.php on line 49

Robert