The Exchange Mail Submission URI

[This is preliminary documentation and subject to change.]

Exchange provides a new process for sending messages using the HTTP/WebDAV protocol and the Web Store OLE DB provider, ExOLEDB. You can send messages using a special Uniform Resource Identifier (URI), called the mail submission URI. A user's mail submission URI is constructed, using whatever URI scheme is appropriate, by appending the ##DavMailSubmissionURI## to the user's personal mailbox URI. For example, you can submit a message for a user with the alias user1 whose mailbox is stored on server1 in the fake.microsoft.com domain through HTTP with the URL http://server1.fake.microsoft.com/exchange/user1/##DavMailSubmissionURI##. Through OLE DB, this URL would be file://./backofficestorage/fake.microsoft.com/MBX/user1/##DavMailSubmissionURI##

To set the message contents, you have the following two options:

• Write the message stream into the item's default stream. With HTTP, you do this with the PUT protocol command. With the OLE DB provider, you retrieve the item's default stream (adDefaultStream in ADO) and write the message stream to it. The stream must be in the format defined by RFC 822 and MIME standards. The stream must also contain the RFC 0821 SMTP protocol commands listed at the beginning:

  MAIL FROM: "User" <user@fake.microsoft.com>
  RCPT TO: "User 1" <user1@fake.microsoft.com>
  RCPT TO: "User 2" <user2@fake.microsoft.com>
  

  The DATA command is not needed and is assumed after the first blank line designated by the first "\r\n\r\n" sequence in the stream.

• Write the properties for the message defined for the urn:content-classes:message content class. This is similar to sending messages using MAPI; the message stream is automatically generated for you by the Web Store when you commit the properties to the item.

Unlike the user's Outbox folder, the mail submission URI is not a folder, nor is it a persisted item for a user's mailbox. It is however, a virtual item used only to transmit messages using any process, including MAPI, HTTP, and OLE DB.

To send messages using this process the sending agent must be authenticated and have the necessary rights to send mail from this mailbox. These credentials include the mailbox owner, and all security principles with the "Send On Behalf Of" right for that mailbox.