import re


def valid_email(address):
    """Check an email address and make sure that it fits the correct format"""
    if not address:
        return False
    match = re.match(r'(?:[a-zA-Z\-_+0-9.]+)@([a-zA-Z0-9_\-]+(?:\.[a-zA-Z0-9_\-]+)+)',
                     address)
    if not match:
        return False
    return True