if ($data[1]) {    # Do you really mean that, by the way?
    my (@t1,@t2); 
    @t1 = map { 
        if (/Error-Handler/) { 
            $_ 
        } else { 
            !/received from internet:/ and push @t2, $_; 
            (); 
        }
    } @data; 
    @data = @t2 if @t1; 
}