In Exchange 2013 you might have a user that needs to Send Email on Behalf of another user. This is quite easy to achieve and can be set from the Exchange Admin Center or the Exchange Management Shell:
Granting Send As access from the EAC:
- Step 1 -> Click on Recipients
- Step 2 -> Click on Mailboxes
- Step 3 -> Click on the mailbox where you want to grant access.
Once you have located the mailbox you can double click it or click on the pencil.
- Once you have the properties window open for the user, the general page will show.
- Click on the mailbox delegation tab on the bottom right.
- Now click the + button under Send on Behalf.
- Once you click the + button the window above will show.
- Select the user that you want to have send on behalf rights and either double click the user account or select it and then click on the add -> button. this will insert the account into the text box highlighted.
- Once done click the ok button.
- As shown above the user you just selected now shows in the box of users that has Send on Behalf Rights.
- Click the Save button for the change to be applied.
- A Please Wait… mini splash screen will appear while the changes are applying.
- Once complete you will return to the screen where all the mailbox are.
Granting Send As Permissions using the Exchange Management Shell:
- Set-Mailbox Test_User2 -GrantSendOnBehalfTo Test_User1
Hope it helps.