Talked about mail content model, and it looks like we'll have (at least) two Kinds: Message (an RFC822 message) and MIME Part (name is TBD).
Still up in the air whether we need separate Kinds for all the various types of MIME
Seems like a delivery status flag (which just so happens to exist in the schema ) can take care of the following states:
Draft (User has created the item but hasn't told the SMTP service to send it)
Ready-to-Send (User has told the SMTP service to send it, but it hasn't attempted to yet -- offline, perhaps)
Sending (We might not need this, but potentially you would want the SMTP service to flag an item with this while it's being processed)
Sent (SMTP service has transferred the message to the SMTP server, with no immediate error)
Retrying (The SMTP service got back a message saying that the SMTP server will keep retrying to deliver the message for a few days -- because the recipient's SMTP server is down, perhaps)
Error (The message could not be delivered)
It will be interesting to see if we can match a bounced message to the original outbound item, which would be cool; that would then take an item from the Sent state to the Error or Retrying states