MAIL$_MESSAGE_AUTO_NEWMAIL
    When you specify the Boolean item code MAIL$_MESSAGE_AUTO_
    NEWMAIL, MAIL$MESSAGE_GET automatically places a new message
    in the mail folder as it is read. MAIL$_MESSAGE_AUTO_NEWMAIL
    is valid only when specified with the item code MAIL$_MESSAGE_
    CONTINUE.
    Specify the value 0 in the buffer length and buffer address
    fields of the item descriptor.
 MAIL$_MESSAGE_BACK
    When you specify the Boolean item code MAIL$_MESSAGE_BACK,
    MAIL$MESSAGE_GET reads the message identification number of a
    specified message to return the first record of the preceding
    message.
    Specify the value 0 in the buffer length and buffer address
    fields of the item descriptor.
    Do not specify the item codes MAIL$_MESSAGE_BACK, MAIL$_MESSAGE_
    CONTINUE, MAIL$_MESSAGE_ID, and MAIL$_MESSAGE_NEXT in the same
    call to MAIL$MESSAGE_GET.
 MAIL$_MESSAGE_CONTINUE
    When you specify the Boolean item code MAIL$_MESSAGE_CONTINUE,
    MAIL$MESSAGE_GET reads the message identification number of a
    specified message to return the next text record of the current
    message.
    Specify the value 0 in the buffer length and buffer address
    fields of the item descriptor.
    Do not specify the item codes MAIL$_MESSAGE_BACK, MAIL$_MESSAGE_
    CONTINUE, MAIL$_MESSAGE_ID, and MAIL$_MESSAGE_NEXT in the same
    call to MAIL$MESSAGE_GET.
 MAIL$_MESSAGE_ID
    MAIL$_MESSAGE_ID specifies the message identification number of
    a message on which an operation is to be performed. The buffer
    address field of the item descriptor points to a longword that
    contains the message identification number.
    Do not specify the item codes MAIL$_MESSAGE_BACK, MAIL$_MESSAGE_
    CONTINUE, MAIL$_MESSAGE_ID, and MAIL$_MESSAGE_NEXT in the same
    call to MAIL$MESSAGE_GET.
 MAIL$_MESSAGE_NEXT
    When you specify the Boolean item code MAIL$_MESSAGE_NEXT,
    MAIL$MESSAGE_GET reads the message identification number of
    a specified message to return the first record of the message
    following the current message.
    Specify the value 0 in the buffer length and buffer address
    fields of the item descriptor.
    Do not specify the item codes MAIL$_MESSAGE_BACK, MAIL$_MESSAGE_
    CONTINUE, MAIL$_MESSAGE_ID, and MAIL$_MESSAGE_NEXT in the same
    call to MAIL$MESSAGE_GET.
 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.