Published: July 16, 2012
Describes a MAPI property.
The ulPropTag member is made up of two parts:
An identifier in the high-order 16 bits.
A type in the low-order 16 bits.
The identifier is a numeric value within a particular range. MAPI defines ranges for identifiers to describe what the property is used for and who is responsible for maintaining it. MAPI defines constraints for each of the property tags that it supports in the Mapitags.h header file.
The type indicates the format for the property's value. MAPI defines constants for each of the property types that it supports in the Mapidefs.h header file.
For a complete list of the valid property ranges for identifiers and property types, see the Property Identifiers and Types appendix.
The dwAlignPad member is used as padding to make sure proper alignment on computers that require 8-byte alignment for 8-byte values. Developers who write code on such computers should use memory allocation routines that allocate the SPropValue arrays on 8-byte boundaries.