This appendix documents functions from the Win32 application programming interface (API) useful in the 16-bit environment used by MAPI client and server developers. Most of the functions documented in this appendix have limitations relative to their Win32 counterparts. Such limitations are noted for each function. Where possible, if the calling implementation requests unsupported functionality, the function returns a value that indicates failure.
Some of the 32-bit Windows functions documented here have been implemented specifically for MAPI. The MAPIWIN.H header file includes definitions to aid in developing single-source service providers that run on both Win32 and Win16 API platforms.
MAPI works only with filenames, and other strings passed to it, in the ANSI character set. Applications that use filenames in the OEM character set must convert them to ANSI before calling MAPI.