code: def email(sender=None, receivers=(), cc=(), bcc=(),
            subject=None, content=None, encoding='utf8',
            attachments=()):
      
      enclosure = [HTML(content, encoding)]
      enclosure.extend(Attachment(k) for k in attachments)
      return Collection(
          *enclosure,
          headers=[
              headers.subject(subject),
              headers.sender(sender),
              headers.to(*receivers),
              headers.cc(*cc),
              headers.bcc(*bcc),
              headers.date(),
              headers.message_id(),
          ]
      )
docs: Creates a Collection object with a HTML *content*,
      and *attachments*.
  
      :param content: HTML content.
      :param encoding: Encoding of the email.
      :param attachments: List of filenames to
          attach to the email.