smtpd.PureProxy.process_message and smtpd.MailmanProxy.process_message are defined to not receive the extra kwargs which they're called with.

They both also expect "data" to be str when it's actually bytes.

Thus they're completed broken at the moment.

I'd like to submit a PR to fix these two bugs.

There are a number of other issues/potential improvements to smtpd which are not critical but I guess should be fixed:
* no support for starttls
* use of print(..., file=DEBUGSTREAM) instead of logger.debug
* no type hints
* PureProxy's forwarding doesn't try starttls

Should I create a new issue(s) for these problems or is there some agreement that only actual bugs will be fixed in little-used modules like this?