Optionally attach incoming message?
Have the originally incoming message attached to the message sent to subscribers (if configured).
Pro:
- Subscribers would be able to verify some signatures by themselves.
Contra:
- Headers would leak to other subscribers
- Encrypted messages can't be decrypted by the subscriber, encrypted+signed neither.
My conclusion right now: it's not worth the effort, because only originally unencrypted messages can be verified at all.