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<concept id="GUID-59217FA7-3078-53CA-88B3-78D6FB788271" xml:lang="en"><title>Message

Type Module Overview</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>Message Type Modules (MTMs) are polymorphic DLL plug-ins that implement

the interfaces defined by the Message Server framework to handle various message

types—such as, IMAP4, POP3, SMTP, SMS and MMS. </p>

<section><title>Purpose</title> <p>Client applications can access different

types of message and every message type must handled in a specific way. To

support a new message type within the client applications, MTMs to implement

that type must be provided. The following points are specific to each message

type, and so must be implemented in an MTM: </p> <ul>

<li id="GUID-B47F5D1A-1C45-56FE-8074-D48F8B72AA58"><p>Message structure </p> </li>

<li id="GUID-39DEC177-3210-5ED2-8095-32728E33EF7A"><p>User interface requirements </p> </li>

<li id="GUID-3BA20B3C-0922-515D-8E11-B5A7336CE263"><p>Addressing mechanism </p> </li>

<li id="GUID-3ADE85A9-3BF2-50F0-9A94-01002A440CF9"><p>Error handling mechanism </p> </li>

<li id="GUID-E0E95CA4-EB36-5D90-8313-CC608ED2ABF1"><p>MTM DLL information </p> </li>

</ul> <p>A Message Server abstraction that is used to locate and load particular

MTM components. </p></section>

<section><title>Description</title> <p>The MTM architecture is the plug-in

scheme provided by the Messaging Framework to integrate different message

transports to the Message Server. The plug-in scheme consists of four interfaces,

the UI MTM, UI Data MTM, Client MTM and Server MTM. </p> <ul>

<li id="GUID-A2763364-A20D-52B4-99FB-5D08747C22B4"><p>Client MTM manages the

message type’s data model, providing the UI MTM and client applications with

interfaces to access and to search for messages. </p> </li>

<li id="GUID-BCF8AD0F-42D9-55D3-92DE-998FBD97E5E9"><p>User Interface (UI)

Data MTM provides icons, menu text and a list of capabilities for a message

type. </p> </li>

<li id="GUID-66AFF19F-1ED2-5AF4-A079-5C8B5344E557"><p>User Interface (UI)

MTM implements the user interface required for the message type, including

a viewer, editor and dialog settings. </p> </li>

<li id="GUID-6C73D1B2-A6F6-5F26-A814-6BD38F43DE3B"><p>Server MTM provides

message transport over the network and manages a queue of outstanding client

requests, and ensures that more than one message of a given type is sent simultaneously. </p> </li>

</ul> <p>Each of the MTM DLLs is a polymorphic DLL that exports an instance

of a system-defined base class. The Message Server and client applications

use these base class interfaces to access MTM functionality in a generic and

extensible way. The MTM in turn implements a specialized version of the class

to provide specific message type functionality. </p> <p>Client applications

can load and use the UI MTM, UI Data MTM and Client MTM DLLs. The DLLs are

loaded within the client’s process space. The Server MTM DLLs are loaded within

the Message Server process. The Messaging Middleware architecture allows clients

to access the combined functionality of the Message Server and the Server

MTMs through a single server interface. The following figure shows the MTM

architecture. </p> <fig id="GUID-D9869871-08F2-5601-8A9C-1871D2AB4E1B">

<title>              MTM architecture            </title>

<image href="GUID-9E9C00E1-00A2-5248-946B-D3AE182F44EC_d0e489232_href.jpg" placement="inline"/>

</fig> </section>

<section><title>Message Server and MTMs</title> <p>The following figure shows

the relationship between the Message Server and MTMs. The grey classes are

realisations of the MTM interfaces defined by the Messaging Framework. The

Message Server depends on the Server MTM interface and controls access to

message data and delegates protocol-specific requests to Server side MTMs.

Messaging clients depend on the Client, UI and UI Data MTM interfaces and

the Message Server client API. </p> <fig id="GUID-F743115B-6934-5026-9D15-8DA5BE3A2D6F">

<title>              Relationship between Message Server and MTMs        

   </title>

<image href="GUID-5059C3F9-1CEA-5DF3-914A-B99376570242_d0e489248_href.jpg" placement="inline"/>

</fig> </section>

<section><title>MTM class summary</title> <p>Messaging Middleware provides

the following base classes, which defines the component interfaces for MTM

implementations. </p> <ul>

<li id="GUID-B72EC9B2-DC51-502F-A23C-303597405B13"><p>The base class for UI

MTMs is <xref href="GUID-A5982338-A057-3870-8832-F503AEAC470A.dita"><apiname>CBaseMtmUi</apiname></xref>. </p> </li>

<li id="GUID-5549337B-621D-52F0-A19F-A0EA61816486"><p>The base class for UI

Data MTMs is <xref href="GUID-899C6D87-5712-34A7-902C-EA452894700C.dita"><apiname>CBaseMtmUiData</apiname></xref>. </p> </li>

<li id="GUID-D2E07F67-69DF-54A8-A7E2-3EA64FD74D3C"><p>The base class for Client

MTMs is <xref href="GUID-177AF50B-14EF-3C45-AE22-1FEE5678261D.dita"><apiname>CBaseMtm</apiname></xref>. </p> </li>

<li id="GUID-42B1BC77-0D29-5627-93C2-CDCC02417B2F"><p>The base class for Server

MTMs is <xref href="GUID-D088273D-FAFE-30F6-8D0A-3A62D3DE62FD.dita"><apiname>CBaseServerMtm</apiname></xref>. </p> </li>

</ul> <p> <b> Important:</b> MTMs can also provide message type-specific functionality

that is not defined by the base class interfaces. For example, for IMAP4,

perform a full synchronization with a remote service; for POP3, connect to

a remote server and download messages. The APIs for the client interfaces

are extensible through run time type information provided by the <xref href="GUID-B3B2885E-DB79-3047-BCD9-C2A9BF08F5FD.dita"><apiname>QueryCapability</apiname></xref> API,

and the <xref href="GUID-41E5C23D-CD5A-3DD3-BFCE-F8C576CE2149.dita"><apiname>InvokeAsyncFunction</apiname></xref> and <xref href="GUID-88DEB665-B4B1-3F73-A2A9-44E72C8514B4.dita"><apiname>InvokeSyncFunction</apiname></xref> APIs. </p> <p>For

information on how to implement the base classes, see the <xref href="GUID-F3E5D412-BEB5-4E0F-9CDE-1DF3F9302BC3.dita">Implementing

MTMs</xref>. </p> </section>

<section><title>MTM functions</title><p>The MTM DLLs provide the following

functions. MTMs implement them according to the requirements for the message

type: </p><ul>

<li id="GUID-56E24547-DA0C-5B01-B68C-4A928D07802F"><p>Querying functionality </p> <p>Allow

the client applications to query the supported functionality for the message

type. For example, the maximum message size or whether attachments are supported. </p> </li>

<li id="GUID-110AFD4C-09D8-585D-B078-6DCD1A4525B4"><p>Message management functionality </p> <p>Allow

the client applications to manage the messages, for example, to send, reply

and forward messages. </p> </li>

<li id="GUID-92F32F80-8E5F-56F9-B35B-99A2934C50E5"><p>Attachment management

functionality </p> <p>Allow the client applications to handle attachments.

For example, to add, remove or create an attachment for a particular message. </p> </li>

</ul></section>

</conbody><related-links>

<link href="GUID-B394A824-8745-505E-8429-8B9B6D418387.dita"><linktext>Message Server

and Store</linktext></link>

<link href="GUID-400E4702-973A-5CAC-9F9C-3A10121F856A.dita"><linktext>Types of

MTM</linktext></link>

<link href="GUID-F3E5D412-BEB5-4E0F-9CDE-1DF3F9302BC3.dita"><linktext>Implementing

MTMs</linktext></link>