Symptoms
Consider the following scenario:
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In an Exchange Server 2010 environment, User A is the delegate of a resource mailbox.
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User B sends a meeting request that contains French characters (or other special characters) to the resource mailbox for booking.
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As the delegate of the resource mailbox, a meeting request is sent to User A for approval.
In this situation, User A receives the meeting request. However, the French characters in the message body of the meeting request are displayed as question marks (?).
Cause
This issue occurs because the forward notification was prefixed with an HTML message that causes the message to be treated as Plain text. This causes data loss.
Resolution
To resolve this issue, install the following update rollup:
2866475 Description of Update Rollup 2 for Exchange Server 2010 Service Pack 3 Note After you apply this update rollup in Exchange Server 2010, the text of the forward notification does not appear on the meeting request that is forwarded to the delegate for approval. 
