kit@gateway.mitre.ORG (06/14/90)
I am working at MITRE Corporation, working on some issues for a messaging system for Department of Defense. I had some questions about how actual X.400 implementations supported some features. Note that I understand the protocol specifications; I am interested in implemetations, not theory, here. Thank you in advance. Kit Lueder, MITRE Corporation. Phone 703-883-5205. 1. Support of alternate recipient assignment. How is the alternate recipient identified--in the directory, in some other non-X.500 table? Can specific alternate recipients be assigned for each actual recipient, or is it more of a "dead letter office" where all undeliverable mail gets dropped? Can the alternate recipient reside on another Message Transfer Agent (MTA), or must it be on the same MTA as the originally intended recipient? 2. Multiple connections of UA to MTA. Can a Remote UA be connected to more than one MTA? If so, can it still have the same ORName/ORAddress regardless of which MTA it uses? 3. Gateways and end-to-end DN/NDN. If you have a gateway from X.400 into the non-X.400 world, can you have the DN/NDN (Delivery Notice, Non-Delivery Notice) go end-to-end, so that the X.400 message originator does not get a notice back until the message was successfully (or not) delivered to the non-X.400 end system? Or does the DN/NDN get triggered when the MTA gives the message to the first gateway, regardless of what happens to the message after it passes through the gateway? 4. Co-located UA/MS. Is a co-located UA and MS (Message Store) any different than just a UA by itself (if there is no visible P7 protocol)? 5. Probe knowledge of UA status. When an MTA receives an X.400 Probe which identifies a recipient supported by that MTA, how much knowledge does the MTA have about that recipient's UA status? Can the MTA know that the UA is down (especially in the case where the UA is remote), and thus do an NDN, even though the recipient name is registered correctly?