To perform this procedure, the account you use must be delegated the following:

• Exchange View Only Administrator or higher and Account Operator or higher
  

For more information about permissions, delegating roles, and the rights that are required to administer Exchange 2007, see Permission Considerations.

Also, before you perform this procedure, be aware that you cannot send e-mail messages on behalf of a mailbox if the mailbox is hidden from address lists. When sending a message, Exchange requires that an e-mail address is resolved in the From field. In the case where a message is sent on behalf of a mailbox that is hidden from address lists, the SMTP address is interpreted as an address that is not from your organization (known as a foreign address) and is rejected. For information about how to change your mailbox settings, see Managing Mailbox Features.

In Microsoft Office Outlook, users will receive the following errors when attempting to send a message on behalf of a mailbox that is hidden from address lists:

• Online mode   When users press Send, they will receive the following error: "You do not have permission to send on behalf of the specified user."
  
• Cached Exchange Mode   Outlook initially sends the message, but users will receive a non-delivery report (NDR) containing the following message: "You are not allowed to send this message because you are trying to send on behalf of another user without permission to do so. Please verify that you are sending on behalf of the correct sender, or ask your system administrator to help you get the required permission"
  

Exchange 2007 SP1

 To use the Exchange Management Console to grant a user the Send As permission for another user's mailbox

1. Start the Exchange Management Console.

2. In the console tree, click Recipient Configuration.

3. In the result pane, select the mailbox for which you want to grant the Send As permission.

4. In the action pane, under the mailbox name, click Manage Send As Permission. The Manage Send As Permission wizard opens.

5. On the Manage Send As Permission page, click Add.

6. In Select User or Group, select the user to which you want to grant the Send As permission, and then click OK.

7. Click Manage.

8. On the Completion page, the Summary states whether the Send As permission was successfully granted. The summary also displays the Exchange Management Shell command that was used to grant the Send As permission.

9. Click Finish.

 To use the Exchange Management Shell to grant a user the Send As permission for another user's mailbox

• Run the following command.

  Add-ADPermission "Mailbox" -User "Domain\User" -Extendedrights "Send As"

For detailed syntax and parameter information, see the Add-ADPermission reference topic.

Exchange 2007 RTM

 To use Active Directory Users and Computers to grant a user the Send As permission for another user's mailbox

1. On a computer that is running Exchange, click Start, point to All Programs, point to Administrative Tools, and then click Active Directory Users and Computers.

2. In Active Directory Users and Computers, on the View menu, click Advanced Features.

3. Expand the domain node, and then click Users.

4. In the details pane, right-click the user for which you want to grant the Send As permission, and then click Properties.

5. In <User> Properties, on the Security tab, click Advanced.

6. In Advanced Security Settings for <User>, click Add.

7. In the Enter the object name to select box, type the name of the mailbox user or the group to which you want to grant the Send As permission, and then click Check Name to verify the user or group. Click OK.

8. In Permission Entry for <User>, in the Apply onto list, select This object only.

9. In the Permissions list, locate Send As, and then select the Allow check box.

10. Click OK to close the dialog boxes.

 To use the Exchange Management Shell to grant a user the Send As permission for another user's mailbox

• Run the following command.

  Add-ADPermission "Mailbox" -User "Domain\User" -Extendedrights "Send As"

For detailed syntax and parameter information, see the Add-ADPermission (RTM) reference topic.

For more information about granting Microsoft Outlook permissions, see Delegate Access Permissions in Outlook Help.