Supporting Messaging Clients

Set Per-User Options

In some situations you may need to override server defaults for specific clients. For example, if the majority of your IMAP4 clients can interpret HTML, you can set the server to provide message bodies in HTML by default. However, if a few clients using the IMAP4 server cannot interpret HTML, you can override the Multipurpose Internet Mail Extensions (MIME) encoding set on the server and provide plain text messages for those clients. Overriding server defaults at the user level allows you to support clients with different needs that access the same IMAP4 virtual server.

Note   You can also create additional virtual servers on a single computer to provide administration for several messaging scenarios. This solution may be best suited for a large number of clients with varying needs.

To set per-user options:

  1. Start Active Directory Users and Computers
    on the Start menu, point to Programs, point to Administrative Tools, and then click Active Directory Users and Computers.

  2. Tip  If Active Directory Users and Computers doesn't appear on the Administrative Tools menu, on the Start menu, click Run, type dsa.msc, and then click OK.

  3. On the View menu, click Advanced Features.
  4. In the console tree, click Users.
  5. In the details pane, right-click a mailbox-enabled user, and then click Properties.
  6. Open Exchange Advanced, and then click Protocol Settings.
  7. Click IMAP4, and then click Settings.
  8. Click Use protocol defaults to clear the check box and configure client settings.
  9. Click Enable for mailbox to clear the check box and disable the access to the mailbox through an IMAP client.
  10. You can override the following server settings for the specific user:
  11. Settings Description
    MIME Encoding MIME provides a way to describe a message consisting of different parts. By definition, all IMAP4 clients are MIME-aware. Options include:
    • Provide message body as plain text.
    • Provide message body as HTML.
    • Both.
    Default character set Exchange supports multilingual messages using Windows code pages instead of Internet character sets. Most languages have a one-to-one correspondence between the character set and code page. If multiple character sets exist for one code page, Exchange uses the character setting specified on the Message Format tab.

    Note   Early MAPI clients, such as Outlook 97, do not allow the user to specify a character set. Character set conversion settings apply for these clients only.

    Use Microsoft Exchange Rich Text Format If enabled, IMAP4 clients receive messages in Exchange Rich Text Format (RTF). Although all IMAP clients receive the information as an attachment, the attachment is opened and displayed as a normal message for IMAP clients that understand Exchange RTF. For IMAP clients that do not understand Exchange RTF, an attachment is displayed.
    Include all public folders when a folder list is requested By default, Exchange lists all public folders in response to the IMAP4 LIST ""* command. To improve performance for clients that have problems listing a large number of folders, list only the client's private folders.
    Enable fast message retrieval By default, Exchange calculates the exact size of a message. To increase the speed of message retrieval for clients that do not require exact message size reports, you can enable the server to approximate message sizes.