<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def clean_text(self, email, **kwargs):
 """Parse and normalize an email address. Returns None if this is not an email address. """

        if not self.EMAIL_REGEX.match(email):
            return None
        email = strip_quotes(email)
        mailbox, domain = email.rsplit('@', 1)
        domain = self.domains.clean(domain, **kwargs)
        if domain is None or mailbox is None:
            return
        return '@'.join((mailbox, domain))