Consider the follow scenario:
In an Exchange Server 2010 environment, a user has a mailbox (MB1).
You grant the user "Send As" or "Send on behalf" permissions for another mailbox (MB2).
The user sends a message from MB1 on behalf of MB2.
In this scenario, the message is only copied to the Sent Items folder in MB1. You cannot configure Exchange Server 2010 so that the message is copied to the Sent Items folder of both MB1 and MB2.
This issue occurs because Exchange Server 2010 was designed to copy messages to the Sent Items folder of the sender only.
To resolve this issue, install the following update rollup:
2706690 Description of Update Rollup 4 for Exchange Server 2010 Service Pack 2 This rollup introduces the following new Exchange PowerShell cmdlets:
Get-MailboxSentItemsConfiguration <mailbox id>
This cmdlet displays the configuration of the Sent Items folder in a specified mailbox.
Set-MailboxSentItemsConfiguration <mailbox id> [-SendAsItemsCopiedTo [Sender|SenderAndFrom]] [-SendOnBehalfOfItemsCopiedTo [Sender|SenderAndFrom]]
This cmdlet enables an administrator to configure the Sent Items folder to which a message is copied.
SendAsItemsCopiedTo changes where messages that are sent by using the "SendAs" permissions are copied.
SendOnBehalfOfItemsCopiedTo changes where messages that are sent by using the "Send on Behalf Of" permissions are copied.
Each command can use:
Sender Copies the message to the Sent Items folder of the sender only
SenderAndFrom Copies the message to the Sent Items folder of both the sender and the user on whose behalf the message was sent
Important The setting may be overridden when the following condition is true:
The DelegateSentItemsStyle registry key is set to a value of 1 on the Microsoft Outlook client.
You must manually change the attributes on mailboxes that existed before the update was applied. To do this, use the commands that are listed earlier in this article.
You must restart the Microsoft Information Store service for the change to take effect immediately.
Currently, you can configure Exchange Server 2010 to copy messages to either the Sent Items folder of the sender or the Sent Items folders of both the sender and the user on whose behalf the message was sent.
The SendAsItemsCopiedTo and SendOnbehalfofItemsCopiedTo settings are applied only if SendAs or SendOnBehalfOf rights are assigned to a specific user directly. If the SendAs or SendOnBehalfOf right is assigned to a distribution group, the sent item will be put in the sender's Sent Items folder only.
Microsoft has listened to customer feedback about messages that are sent by using the "SendAs" and "SendOnBehalfOf" permissions, and we have changed our product to better serve the needs of our customers
For more information about how to manage the "Send As" permissions for a mailbox, go to the following Microsoft website:
Manage "Send As" permissions for a mailbox
For more information about the DelegateSentItemsStyle registry value, click the article number to view the article in the Microsoft Knowledge Base:
2703723 Email remains in the Outbox when you use the DelegateSentItemsStyle registry value