A message store serves as a local archive for storing messages on Windows Mobile devices. One message store is present for each messaging account, and each messaging account is associated with one message transport. For example, you might use a Windows Mobile device to service three POP3 e-mail accounts. In this scenario, you might have four message stores: one for Outlook e-mail transferred through ActiveSync, two for Outlook e-mail transferred via POP3, and one for text messages transferred via Short Message Service (SMS).
Windows Mobile devices running Windows Mobile 2003 Second Edition software and later come with a message store for e-mail called Outlook E-Mail. Phone-enabled devices come with another message store for Short Message Service (SMS) text messages called Text Messages. On devices running Windows Mobile 2003 software and earlier, these message stores are called ActiveSync and Short Message Service (SMS), respectively.
Message stores are divided into folders for containing and managing collections of Message items. Inbound messages arrive at a designated receive folder. In the Windows Mobile Messaging application, it is named Inbox.
Messaging client applications communicate with message stores using methods on the IMsgStore interface. Through this interface, you can do the following:
Open folders and messages and acquire an interface pointer to them for further processing (IMAPIFolder for folders and IMessage for messages).
Get, set, and delete folder and message properties.
Register to receive notifications of specified events that indicate changes to the message store contents.