Consider the following scenario:
You create a user A account in a non-English Microsoft Exchange Server 2010 environment.
You create a user B account in an English Microsoft Exchange Server 2010 environment.
You configure the DisplayName property of user A to use a double-byte character set (DBCS).
You configure the SimpleDisplayName property of user A to use a single-byte character set (SBCS).
User B accesses a mailbox by using Outlook 2010 that is running in ANSI mode with an online profile.
User A sends an email message to user B.
In this scenario, you expect the Simple Display Name value for user A to show in the From field. Instead, the legacyExchangeDN value or the last Common Name value of user A is shown.
Note This issue does not occur in an Exchange Server 2003 environment.
To resolve this issue, install the following update rollup:
2746164 Description of Update Rollup 6 for Exchange Server 2010 Service Pack 2
To work around this issue, you can change the DisplayName property of user A from DBCS to SBCS.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.