Initiates mail file processing.

    Format

      MAIL$MAILFILE_BEGIN  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
    Mail file context information to be passed to other mail file
    routines. The context argument is the address of a longword that
    contains mail file context information.

    You should specify the value of this argument as 0 in the first
    of a sequence of calls to mail file routines. In the following
    calls, you should specify the mail file context value returned by
    this 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 a longword value of 0.

    For this routine, there are no input item codes.

 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.

    The only output item code for this routine is the MAIL$_MAILFILE_
    MAIL_DIRECTORY item code. When you specify MAIL$_MAILFILE_
    MAIL_DIRECTORY, MAIL$MAILFILE_BEGIN returns the mail directory
    specification to the caller. 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$MAILFILE_BEGIN creates and initiates a mail file context for
    calls to other mail file routines.

3  –  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$_ACCVIO         Access violation.
    Any condition value returned by LIB$GET_VM, $GETJPIW, and
    $GETSYI.