When Microsoft Outlook is configured to run in ANSI mode, the display name of a recipient in the To/CC/From field is displayed as the simple display name, and the following issues occur:
The characters of an e-mail subject are corrupted as "???".
The result of sorting in the Address Book is wrong. It is sorted incorrectly by the character code of the display name. However, it should be sorted by the simple display name.
When Outlook is configured to run in Unicode mode, the following issue occurs:
When a user who has Single-Byte Character Set (SBCS) display name sends a message to another user who has Double-Byte Character Set (DBCS) display name and opens the message from the Sent Items folder, the user's alias is displayed in the To/CC field.
To resolve these issues, install Update Rollup 8 for Exchange Server 2010 Service Pack 3.
Note ANSI support is added by installing the following hotfix:
2489941 The "legacyExchangeDN" value is shown in the "From" field instead of the "Simple Display Name" in an email message in an Exchange Server 2010 environment
After you install the update rollup in this article, the ANSI support is removed from Exchange Server 2010.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.