Integer item code specifying an action to be taken by mtaSend(). The include file described in Chapter 1, MTA SDK Concepts and Overview defines these codes. Each item code is described later in this chapter, starting at Item Codes.
The caller-supplied address of data to be used in conjunction with the action specified by the item_code field. Not all actions require that an item_address be supplied.
When the item code has an associated string value, this field optionally provides the length in bytes of the string, not including any NULL terminator. If a value of zero (0) is supplied, then the string pointed to by item_address must be NULL terminated, so that mtaSend() can automatically determine the string’s length.
When the item code has an associated integer value, this field supplies that value.
When the item code MTA_ADR_STATUS is specified, this field will contain processing status for the associated envelope recipient address.
When the item code MTA_ADR_STATUS is specified, this field will contain the rewritten form of the envelope recipient address when the returned value of item_status is zero, or a textual error message when the returned value of item_status is non-zero.