Sending Email from a Secondary Exchange Mailbox

A visitor asked how to send mail from a shared email account:

We have several users that need the ability to view, send and receive emails for different accounts. We can get everything set up correctly except for one piece. Anytime a person sends out an email it is sent from the wrong mailbox and also shows up in the incorrect sent box.... We don't have a selection of which account to send from.

Delegates of shared accounts who can send mail on behalf of and have full control of all the folders in the shared account can save sent items and deleted items in the mailbox owner's folders. However, a registry key may need to be set.

You need to use Cached Exchange mode for this to work!

In all versions of Outlook, there are two basic ways to control where sent mail is saved for the secondary account. Assign the user Send as permissions then save the email to the secondary account's Sent Items folder using rules or a registry value, or add the second account as an IMAP account.

Saving Sent Items in the Shared Mailbox

To save items in the Sent folder with the mailbox open as a secondary mailbox, you will either need to use "After sending" rules or a registry hack. Either way, your default Exchange account will need to have Send as permission and create permission on the Sent items folder.

This applies to Deleted items as well. See Deleted items for the registry key.

First, in the Active Directory, give the user's account send as permission on the accounts he needs to send from. The user then types that address in the From field (or click the From button and select it from the GAL) when preparing the message.

Delegates with permission to send email on behalf of another user should have the correct permission already. However, SendAs permission will eliminate mail being sent "on behalf of" the mailbox owner.

In the secondary mailbox, the user's account will need permission to create items in the Sent Items folder. This can be set from Outlook. Right click on the Sent Items folder and choose Properties, then Permissions tab. The user needs sufficient permissions to create items in the folder.

With Outlook 2003, 2007, or 2010, the sent message can be moved to the secondary account's Sent folder automatically if a registry key is set and appropriate hotfixes or updates are installed.

Users of all version of Outlook can use after sending rules or an add-in to move the sent messages to move sent items to the correct folder.

While you can open secondary mailboxes Outlook 2010, you can also open the account as a second Exchange account. However, we recommend delegates use the "old" method of opening the shared mailbox as a secondary account in their profile.

When the user has Full Access rights to the mailbox, the mailbox is opened in the profile automatically in Outlook 2007 and 2010.

DelegateSentItemsStyle Registry Value

To move sent messages to the correct sent items folder in Outlook 2010, 2007, or 2003, you need to enable a registry setting. (If you have the latest service pack for your version of Outlook, the hofix may be installed.)

Outlook 2016

Open the registry editor and browse to:

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Preferences
DWORD: DelegateSentItemsStyle
Data Value: 1

Outlook 2013

Open the registry editor and browse to:

HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Preferences
DWORD: DelegateSentItemsStyle
Data Value: 1

Outlook 2010

In Outlook 2010, you need to have SP1 (or greater) installed. Open the registry editor and browse to:

HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Preferences
DWORD: DelegateSentItemsStyle
Data Value: 1

Outlook 2007

In Outlook 2007, install the June 30, 2009 hotfix, described in KB article 970944. Then open the registry editor and browse to

HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Preferences
DWORD: DelegateSentItemsStyle
Data Value: 1

Outlook 2003

For Outlook 2003, you need this hotfix package. Once its installed, open the registry editor and browse to

HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Preferences
DWORD: DelegateSentItemsStyle
Data Value: 1

With all versions you will need to close and restart Outlook for the registry change to take effect.

Do It For Me

If you don't want to edit the registry yourself, I have ready-to-use registry files you can download and run to set the DelegateSentItemsStyle.
Outlook 2016 Outlook 2013 Outlook 2010
Outlook 2007 Outlook 2003

Who sent the message?

If you need to know who sent the message, you can add the change by field to the Sent Items folder.

To do this, right click on the row of field names and choose Field Chooser. Select All Mail Fields then find Changed By in the list.

Create a Second Account

If editing the registry to enable the add the DelegateSentItemsStyle registry value is not an option, you can add the additional accounts to the profile as IMAP accounts, then select the account when composing the message.

If you have Outlook 2010, an IMAP account is not necessary as you can add additional Exchange mailboxes to your Outlook profile as additional Exchange accounts. Note that this is not recommended for users with delegate permissions to the mailbox. These users should use either the DelegateSentItemsStyle registry key (or after sending rules) or create an IMAP account.

How to Edit the Registry

Press Windows key + R to open the Run dialog, type regedit and press Enter.

1. Browse the registry and locate HKEY_CURRENT_USER\Software\Microsoft\Office\xx.0\Outlook\Preferences (Where xx is your version of Outlook.)
2. Right click on Preferences key and select New, DWORD Value.
3. Type (or paste) DelegateSentItemsStyle for the DWORD
4. Double click on DelegateSentItemsStyle to open the Edit dialog then type 1 for the Value data and close the dialog.

Don't forget to close and restart Outlook!