my $sql = 'SELECT Email FROM foo';
my $sth = $dbh->prepare($sql);
$sth->execute();

if (my $email = $sth->fetchrow_array()) {
    print "$email\n";
    while ($email = $sth->fetchrow_array()) {
        print "$email\n";
        }
     }
else {
    print "Database empty\n";
    }