Automatic Message Property Promotion
Topic Last Modified: 2006-06-12
The Exchange store automatically sets properties for messaging items when the associated stream is saved. You control this behavior through the file name extension of the item. When you create an item with an .eml extension, and write the item's stream, the Exchange store assumes that the stream is formatted according to the RFC 822 and Multipurpose Internet Mail Extensions (MIME) standards. It examines the inbound stream for various messaging-related values, such as mail header fields and message text, and automatically sets these properties for the item. This is referred to as property promotion; the promotion is from data within the stream to properties for the item. The Exchange store checks the stream for all properties defined by the urn:content-classes:message content class for promotion.
In the following example, you create an item in your inbox with the name mymessage.eml and you also save and commit the following stream to the item in the Exchange store:
To: "User 1" <user1@example.com>
From: "User 2" <user2@example.com>
Subject: My latest draft.
This is the text portion of the message.
The following table lists the properties for the items after saving the stream.
| Property | Value |
|---|---|
"User 1" <user1@example.com> |
|
"User 1" lt;user1@example.com> |
|
User 1 |
|
"User 2" <user2@example.com> |
|
"User 2" <user2@example.com> |
|
user2@example.com |
|
User 2 |
|
My latest draft. |
|
My latest draft. |
|
This is the text of the message. |
|
10/5/98 11:49 AM |
|
10/5/98 11:52 AM |
|
False |
Note
The Exchange store does not automatically update the stream for the message when the properties are changed using OLE DB or Microsoft® ActiveX® Data Objects (ADO). You must update the stream separately. To avoid updating the stream separately, use the Collaboration Data Objects (CDO) Message object or the CalendarMessage object when you modify existing items in the Exchange store. These objects automatically ensure that messaging properties and the item stream remain synchronized.