def whether_in_file(email, rows):
    """
    Check if email is in CSV file.
    :param email: str
    :param rows: list of csv file rows [row0, row1, ...]
    :return: is_in_file: boolen
    """
    is_in_file = False
    for row in rows:
        if email.lower() == row[0].lower():
            is_in_file = True
            break
    return is_in_file