VMS Help MAIL Routines, MAIL$MAILFILE_CLOSE, Input Item Codes  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 MAIL$_MAILFILE_FULL_CLOSE

    The Boolean item code MAIL$_MAILFILE_FULL_CLOSE specifies that
    MAIL$MAILFILE_CLOSE should purge the wastebasket folder when it
    closes the mail file. If the number of bytes deleted by the purge
    operation exceeds a system-defined threshold, the Mail utility
    reclaims the deleted space from the mail file.

    Specify the value 0 in the buffer length and buffer address
    fields of the item descriptor.

    The system-defined threshold is reserved by Compaq.

 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.