MAIL$_MESSAGE_BINARY_DATE
    When you specify MAIL$_MESSAGE_BINARY_DATE, MAIL$MESSAGE_GET
    returns the message arrival date as a quadword binary value.
 MAIL$_MESSAGE_CC
    When you specify MAIL$_MESSAGE_CC, MAIL$MESSAGE_GET returns the
    CC: field of the current message. The buffer address field of
    the item descriptor points to a buffer that receives a character
    string 0 to 998 characters long.
    Specify a value from 0 to 998 in the buffer length field of the
    item descriptor.
 MAIL$_MESSAGE_CURRENT_ID
    When you specify MAIL$_MESSAGE_CURRENT_ID, MAIL$MESSAGE_GET
    returns the message identification number of the current message.
    The buffer address field of the item descriptor points to a
    longword that receives the message identifier number.
 MAIL$_MESSAGE_DATE
    When you specify MAIL$_MESSAGE_DATE, MAIL$MESSAGE_GET returns
    the message creation date string. The buffer address field of
    the item descriptor points to a buffer that receives a character
    string 0 to 255 characters long.
    Specify a value from 0 to 255 in the buffer length field of the
    item descriptor.
 MAIL$_MESSAGE_EXTID
    MAIL$_MESSAGE_EXTID specifies the external message identification
    number of the current message. The buffer address field of the
    item descriptor points to a buffer that contains a character
    string 0 to 255 characters long.
 MAIL$_MESSAGE_FROM
    When you specify MAIL$_MESSAGE_FROM, MAIL$MESSAGE_GET returns the
    From: field of the specified message. The buffer address field of
    the item descriptor points to a buffer that receives a character
    string 0 to 998 characters long.
    Specify a value from 0 to 998 in the buffer length field of the
    item descriptor.
 MAIL$_MESSAGE_RECORD
    When you specify MAIL$_MESSAGE_RECORD, MAIL$MESSAGE_GET returns
    a record of the message. The buffer address field of the item
    descriptor points to a buffer that receives a character string 0
    to 998 characters long.
    Specify a value from 0 to 998 in the buffer length field of the
    item descriptor.
    MAIL$_MESSAGE_RECORD is valid only when specified with the item
    code MAIL$_MESSAGE_CONTINUE.
    Do not specify MAIL$_MESSAGE_RECORD with the following item
    codes:
    o  MAIL$_MESSAGE_BACK
    o  MAIL$_MESSAGE_ID
    o  MAIL$_MESSAGE_NEXT
 MAIL$_MESSAGE_RECORD_TYPE
    When you specify MAIL$_MESSAGE_RECORD_TYPE, MAIL$MESSAGE_
    GET returns the record type. A record may be either header
    information (MAIL$_MESSAGE_HEADER) or text (MAIL$_MESSAGE_TEXT).
    The buffer address field of the item descriptor points to a word
    that receives the record type.
 MAIL$_MESSAGE_RETURN_FLAGS
    When you specify MAIL$_MESSAGE_RETURN_FLAGS, MAIL$MESSAGE_GET
    returns the Mail system flag for the current message as a 2-byte
    bit mask value.
 MAIL$_MESSAGE_SENDER
    When you specify MAIL$_MESSAGE_SENDER, MAIL$MESSAGE_GET returns
    the name of the sender of the current message. The buffer address
    field of the item descriptor points to a buffer that receives a
    character string 0 to 998 characters long.
    Specify a value from 0 to 998 in the buffer length field of the
    item descriptor.
 MAIL$_MESSAGE_SIZE
    When you specify MAIL$_MESSAGE_SIZE, MAIL$MESSAGE_GET returns the
    size in records of the current message as a longword value.
 MAIL$_MESSAGE_SUBJECT
    When you specify MAIL$_MESSAGE_SUBJECT, MAIL$MESSAGE_GET returns
    the Subject: field of the specified message. The buffer address
    field of the item descriptor points to a buffer that receives a
    character string 0 to 998 characters long.
    Specify a value from 0 to 998 in the buffer length field of the
    item descriptor.
 MAIL$_MESSAGE_TO
    When you specify MAIL$_MESSAGE_TO, MAIL$MESSAGE_GET returns the
    To: field of the specified message. The buffer address field of
    the item descriptor points to a buffer that receives a character
    string 0 to 998 characters long.
    Specify a value from 0 to 998 in the buffer length field of the
    item descriptor.