Adds an attribute, such as Subject or To, to the message you are
    currently constructing.

    Format

      MAIL$SEND_ADD_ATTRIBUTE  context ,in_item_list ,out_item_list

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

    Longword condition value. All utility routines return a condition
    value in R0. Condition values that can be returned by this
    routine are listed under Condition Values Returned.

2  –  Arguments

 context

    OpenVMS usage:context
    type:         longword (unsigned)
    access:       modify
    mechanism:    by reference
    Send context information to be passed to send routines. The
    context argument is the address of a longword that contains send
    context information returned by MAIL$SEND_BEGIN.

    You should specify this argument as 0 in the first of a sequence
    of calls to MAIL routines. In following calls, you should specify
    the Send context value returned by the previous routine.

 in_item_list

    OpenVMS usage:itmlst_3
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Item list specifying options for the routine. The in_item_list
    argument is the address of a list of item descriptors, each of
    which specifies an option and provides the information needed to
    perform the operation.

    The item list is terminated by longword value of 0.

3  –  Input Item Codes

 MAIL$_SEND_CC_LINE

    MAIL$_SEND_CC_LINE specifies a descriptor of the CC: field text.
    The buffer address field of the item descriptor points to a
    buffer that contains 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$_SEND_FROM_LINE

    MAIL$_SEND_FROM_LINE specifies a descriptor of the From: field
    text of the message to be sent. The buffer address field of the
    item descriptor points to a buffer that contains a character
    string 0 to 998 characters long.

    Specify a value from 0 to 998 in the buffer length field of the
    item descriptor.

    Calls to MAIL$SEND_ADD_ATTRIBUTE using this input item code must
    be made before any calls to MAIL$SEND_ADD_ADDRESS.

    The SYSPRV privilege is required to alter the From: of a message.

 MAIL$_SEND_SUBJECT

    MAIL$_SEND_SUBJECT specifies a descriptor of the Subject: field
    text of a message to be sent. The buffer address field of the
    item descriptor points to a buffer that contains 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$_SEND_TO_LINE

    MAIL$_SEND_TO_LINE specifies a descriptor of the To: field text
    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.

 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.

4  –  Output Item Codes

    None.

5  –  Description

    If you do not specify a To: line, the Mail utility supplies a
    To: line composed of user names on the To: address list. If you
    do not specify a CC: line, the Mail utility supplies a CC: line
    composed of user names on the CC: address list. In either of the
    above cases, commas separate the user names.

    To add a message's From: field, you must have the SYSPRV
    privilege, and the Mail DECnet object must have the SYSPRV
    privilege on OUTGOING CONNECT (users can set the DECnet object
    privileges at their discretion).

6  –  Condition Values Returned

    SS$_NORMAL         Normal successful completion.
    MAIL$_INVITMCOD    The specified item code is invalid.
    MAIL$_INVITMLEN    The specified item length is invalid.
    MAIL$_MISREQITEM   The required item is missing.
    SS$_ACCVIO         Access violation.