A protocol by Microsoft which stands for Messaging API (Application Programming Interface). It is the both the protocol and the programmability model for the MS Exchange / Outlook relationship. Other mail standards (or more accurately protocols) are POP,IMAP, and SMTP. It shares many common elements to the Microsoft Win32 API, but they perform actions through Outlook, and on the store (See MS Exchange for a definition of the store). The protocol takes heavy advantage of the Windows programming model, although this noder has had no experience with that API model.