Consider the following scenario. You use Microsoft Office Outlook 2010 or a version later than Outlook 2007 SP2 to send an email message in an Exchange Server 2010 environment. Your display name contains double-byte character set (DBCS) characters. In this scenario, the display name is corrupted in Sent Items folder.
This issue occurs because the Information Store service does not generate the PR_SENT_REPRESENTING_NAME address property by using the Unicode format.
To resolve this issue, install the following update rollup:
2645995 Description of Update Rollup 1 for Exchange Server 2010 Service Pack 2
For more information about the MAPI string properties, visit the following Microsoft website: