Common Messaging Calls (CMC)

The Common Messaging Calls (CMC) applications programming interface (API) provides a simple and convenient set of functions for applications that need basic messaging functionality. CMC provides for all the major messaging functionality an application should need, such as accessing message stores for sending and receiving messages, and addressing and name resolution services. The functions in the CMC API are typically high level functions and can each be used in several different ways depending on the arguments to the functions. The CMC API makes it possible for the calling application to know nothing about the underlying messaging system or transport mechanism used to implement the CMC API itself.

Most CMC functions use both input and output parameters. Input parameters provide information the CMC implementation uses to perform the tasks needed by the calling application. The CMC implementation uses output parameters to pass information back to the calling application from a CMC function. Some functions have parameters used for both input and output.

Data structures and symbolic constants for CMC and its extensions are described in this reference. Their C language definitions can be found in the following header files:

Header file name

Header file contents

XCMC.H

CMC data structures and symbolic constants.

XCMCEXT.H

Common CMC extension data structures and symbolic constants.

XCMCMSXT.H

Microsoft CMC extension data structures and symbolic constants.