This is one in a series of blog posts describing new features of Isode’s R14.6 release, scheduled for March 2010. You can see all posts relating to R14.6 by clicking this link.
We are adding a new configuration option in M-Switch with GUI configuration from MConsole for an entity that has characteristics of both X.400 User Agent and X.400 Distribution List (DL).
When receiving messages, this address will act like a DL, with messages being delivered to multiple users. However, unlike a standard DL there is an associated “normal” UA with the same address that can send messages.
The primary driver for this capability is Aviation (AMHS) to support configurations that emulate older AFTN configurations that have addresses which behave in this way.
The core setup of this entity is as a DL, with members and management as a normal DL. There is also a special UA (address) associated with the DL that has a “private address”. This private address is a member of the DL and is used to deliver messages to the associated UA. Having this separate address ensures that there are no loops.
The M-Switch configuration associates BOTH the list address and the private address with the UA. The UA (which can be a standard P3 or P7 UA) will bind using the same address as the DL, and so will be able to send messages from the DL address. M-Switch (for P3) and M-Store X.400 (for P7) will make available messages sent to the private address (so essentially both list and private address are associated with the UA). This means that the UA can be configured as if it has the same address as the DL and will be able to send and receive messages.
For someone sending to the UA/DL address, it will just be “an address”, noting that positive and negative delivery reports will make it look like a DL (positive delivery reports will indicate “expanded”).
The UA associated with the DL will see all messages received as coming via the DL (there will always be DL expansion history). The “this-recipient-name” parameter will be set to the private address, so the UA will be able to detect the “special” behaviour. This is unlikely to have any effect on the UA. If it is desired to have the UA send IPNs (Inter Personal Notifications) to record message receipt, the UA will need to be adapted for this special UA/DL configuration. A standard UA will not send IPNs where a message has been delivered via a DL. The UA will need to recognize this case as special if it is desired to use IPNs.