INFO: MSMQ Is Not an E-mail Product Competing with Exchange Server

MORE INFORMATION

MSMQ is a development tool that includes a store and forward protocol model to be used for developing messaging applications. Exchange Server is a messaging application that enables message interaction between people. MSMQ is not an e-mail server positioned to compete with any of the existing Microsoft e-mail solutions. These e-mail solutions can be used for complementary solutions targeted at different communication needs. For example, Exchange Server moves electronic letters between Exchange Server users, using a postoffice and mail folders. MSMQ moves data messages between applications, using a system of store-and-forward queues. MSMQ complements Exchange Server, Microsoft Messaging, and MAPI clients by interoperating with them, allowing the different clients to communicate.

The remainder of this article compares key similarities and differences between MSMQ and e-mail in general.

Key Similarities with E-mail

• Asynchronous: Clients of both technologies need not be present (or running) for a message to be sent to them. Messages are stored until the recipient is available, then forwarded to them.
• Addressing: Both types of messages indicate the address of sender and receiver.

Key Differences with E-mail

• Application-to-application: The MSMQ client is an MSMQ application, whereas an e-mail client is generally a person.
• The message body is data: The MSMQ message body is data, typically understood only by the applications that process the message. An e-mail message body is generally an electronic letter, understood by any person who reads it.
• Connectionless: The MSMQ application does not need to be online to send messages. E-mail clients typically need a connection to their server or postoffice to send e-mail.
• Simple, small and fast: MSMQ is optimized to provide the throughput required by enterprise applications.
• Stronger guarantees than e-mail: MSMQ provides prioritized, guaranteed delivery and acknowledgments.
• More delivery options: MSMQ provides options for express, disk based, and transactional delivery.

Complementary Functionality

MSMQ complements and extends e-mail functionality by allowing the different clients to communicate. For example, the MSMQ Exchange Connector connects an MSMQ enterprise to a computer running Exchange Server, allowing users of Exchange Server to send e-mail messages to an MSMQ application, and vice versa. The MSMQ MAPI Transport provides the same functionality for MAPI clients. The MSMQ Mail SDK provides C and ActiveX APIs for creating and parsing messages in a subset of the MIME format. For more information about the MSMQ Exchange Connector, MSMQ MAPI Transport and MSMQ Mail SDK, consult the online "MSMQ Administrator's Guide" and MSMQ SDK Help.