ISSUE: what do we do about tracking when an address is expanded?

The problem:

When we send a mail message to one or more recipients that are exploded 
either as the result of an alias expansion or a list expansion (note that 
this may be the same thing for some MTA's), what do we do about tracking 
the message?

My opinion:

The following discussion is based on the parts of the model that we 
reached concensus on in Oslo.   Most of this is reflected in Tony's notes,
but until we have a new draft, some of the detail may be lacking.   Also, 
concensus reached in Olso is based on a small design team group, and is 
open to discussion by the general list.   

For the iteractive (query) based tracking, we follow the path that the 
message takes from MTA to MTA.   Whether we support a referral or a 
chaining model for the tracking query (another open issue) one of the 
tracking entities will still have to follow multiple recipient address 
paths for the message.   If the message originates with multiple 
recipients, then multiple tracking paths will need to be followed from the
start.   If one of the recipients explodes into multiple addresses then 
presumably we will have the capability to track all the resulting paths if
we want to do so.

So, the question resolves to one of policy: do we want to track a message 
beyond an expansion?   The answer might be different for aliases and lists.
Particularly for public mailing lists.

I'll put a stake in the ground by saying that we should do at list and 
alias boundaries whatever DSN does.   We had good concensus on the 
relationship between DSN and message tracking -- basically DSN is passive/
asynchronous/pre-hoc message tracking whereas the new protocol extends that
to do active/synchronous/post-hoc message tracking.   It makes sense to me
that they should follow the same rules.

Cheers.
---
Steve Hole
Messaging Direct
Mailto:[email protected]
Phone: 780-424-4922