With the release of Exchange 2010 SP3, you can now control where sent items are stored when Send-As or Send-on-Behalf permissions are configured and you’re using Outlook Web Access. In Outlook we already had the possibility to control where sent items are stored this using registry keys, but now we can do so from Outlook Web Access or using the Exchange Management Shell. Unlike Outlook, you unfortunately can’t control where deleted items are stored.

As a quick reminder, to configure permissions for user Francis to send e-mail messages as Philip or on behalf of Philip, you would use:

Add-ADPermission Philip -User Francis -Extendedrights "Send As"
Set-Mailbox Philip -GrantSendOnBehalfTo Francis

Sent Items Management from Outlook Web Access
To access the Sent Items Management option, use OWA to open the (shared) mailbox and navigate to Settings > Sent Items

You can configure the following options for Send-As or Send-on-Behalf e-mail:

• From mailbox: The sent item will be stored in the Sent Items folder of the (shared) mailbox;
• Sender and From mailboxes: The sent item will be stored in the Sent Items folder of the (shared) mailbox and actual sender;
• Sender mailbox: The sent item will be stored in the Sent Items folder of the actual sender (default).

Sent Items Management using EMS
To inspect where sent items are stored, use Get-MailboxSentItemsConfiguration, e.g.

Get-MailboxSentItemsConfiguration Philip

To configure the settings, use Set-MailboxSentItemsConfiguration in conjunction with SendAsItemsCopiedTo or SendOnBehalfOfItemsCopiedTo specifying Sender, From or SenderAndFrom. For example, to configure the items sent as Philip to be stored in the mailbox of both Philip and the actual sender, use the following cmdlet:

Set-MailboxSentItemsConfiguration Philip –SenderAndFrom

It would be nice if Outlook would honor these settings, just like the signatures, so you configure this centrally and have consistent behavior regardless of the client setting. It shouldn’t be difficult, using Exchange Web Services as a vehicle to store and retrieve this information.