component email-gateway: first draft: Initial implementation of the Email Gateway. This component uses XEP-0100 for registration. Upon registration and subsequent startups, a connection is made to registered IMAP services, and incoming emails (in `INBOX` mailboxes) are immediately forwarded as XMPP messages. In the opposite direction, an SMTP connection is established to send emails on incoming XMPP messages. rel 449

from typing import Optional

from twisted.words.xish import domish


class BaseError(Exception):
    namespace: str
    condition: str
    text: Optional[str]
    textLang: Optional[str]
    appCondition: Optional[domish.Element]

class StanzaError(BaseError):
    ...