Users cannot read calendar items when they connect Exchange Server 2007 by using certain IMAP4 or POP3 clients

When users connect to Microsoft Exchange Server 2007 by using IMAP4 or POP3 clients, all calendar items that are retrieved use UTF-8 encoding. This includes the body part of the message in the MIME format. It also includes the iCalendar body part (.ics attachment) that uses the iCalendar RFC 2445 standard to describe the calendar item. However, some IMAP4 and POP3 clients, such as some mobile devices, cannot read the calendar items.

To resolve this problem, install Update Rollup 7 for Exchange 2007 Service Pack 1.

For more information about Update Rollup 7 for Exchange Server 2007 Service Pack 1, see the following Exchange Help topic: For more information about how to obtain the latest Exchange service pack or update rollup, see the following Exchange Help topic: After you apply this hotfix, Exchange Server 2007 provides support to enable the OverrideCalendarMessageCharset option in the IMAP4 or POP3 retrieval settings to specify the character set to be used for encoding the non-iCalendar body parts. This option may be added to the AppSetting section in the Microsoft.Exchange.Imap4.exe.config file or in the Microsoft.Exchange.Pop3.exe.config file for POP3. To enable the OverrideCalendarMessageCharset option, follow these steps:

1. On the server that is running the Exchange Server 2007 Client Access Server (CAS) role, open Windows Explorer.
2. Locate the following folder:
   <drive>:\Program Files\Microsoft\Exchange Server\ClientAccess\PopImap
3. Make a backup copy of the Microsoft.Exchange.Imap4.exe.config file or of the Microsoft.Exchange.Pop3.exe.config file.
4. In Notepad, open the Microsoft.Exchange.Imap4.exe.config file or the Microsoft.Exchange.Pop3.exe.config file.
5. In the line between <appSettings> and </appSettings>, insert <add key="OverrideCalendarMessageCharset" value="iso-2022-jp" /> so that the information resembles the following example.

   <configuration> 
    <appSettings> 
   
     <add key="OverrideCalendarMessageCharset" value="iso-2022-jp" />
    
   </appSettings> 
   </configuration>
   

6. Save the changes, and then exit Notepad.
7. Restart the Exchange IMAP service or the Exchange POP service.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.