MAIL$_MAILFILE_RECLAIM
    The Boolean item code MAIL$_MAILFILE_RECLAIM specifies that
    MAIL$MAILFILE_PURGE_WASTE purge the wastebasket folder and
    reclaim deleted space in the mail file.
    Specify the value 0 in the buffer length field of the item
    descriptor.
    MAIL$_MAILFILE_RECLAIM explicitly requests a reclaim operation
    and overrides the deleted byte's threshold regardless of the
    number of bytes deleted during a mail file purge operation.
 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.