On Nov 15, 2007, at 12:10 PM, David F. Skoll wrote:
By providing the TBR Extension, the outbound serve is able to
complete their transaction using the TBR verb now rather than the
DATA verb at some point later. This eliminates any need to retry.
But it still means the sender has to hang on to the message. And
worse, it cannot possibly know when its safe to relinquish it
because mailing-list exploders can cause the number of required
fetches to be indeterminate.
Perhaps retraction of the alternative mode specified in section 3.2
needs to be strengthened.
3.2. TBR Transaction
| As an alternative, instead of retrieving the replacement message
| content, it MAY prepend any additional trace headers to a
| notification sent to the recipient containing the eXAM-URI itself,
| along with any other appropriate information.
: An alternative notification containing the eXAM-URI and not the
: retrieved message content SHOULD NOT be used. The message is not
: delivered unless the message content is retrieved. Exploding the
: number of recipients MUST NOT occur without first retrieving
: message content.