MAIL$_MESSAGE_ID
MAIL$_MESSAGE_ID specifies the message identification number of
the message on which the operation is to be performed. The buffer
address field points to a longword that contains the message
identification number.
The item code MAIL$_MESSAGE_ID is required.
out_item_list
OpenVMS usage:itmlst_3
type: longword
access: write only
mechanism: by reference
Item list specifying the information you want the routine to
return. The out_item_list argument is the address of a list of
item descriptors, each of which describes an item of information.
The list of item descriptors is terminated by longword value of
0.