[[Can anyone help me to know how can I get the value of table LNM$TEMPORARY_MAILBOX, and how can I change its value.]]
When the client nuzzles up with the server, the client can pass over its mailbox unit number in its registration "hello" message.
If the server is looking to field these sorts of incoming requests, it can post (publish) its mailbox unit number in some global place specific to the server and its incarnation. This can be in a file, a lock value block, an explicitly-declared application-specific logical name (lib$set_logical), etc.
