import re


def validate_email(email):
    """Validate email address"""
    re_str = r'^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$'
    match = re.match(re_str, email)
    return match is not None