For exchange 2007 / 2010 (OWA)
Useful if you don’t have the password and can’t change it to get into a mailbox. Typically used for managers or owners auditing employees email activity without alerting the user.
- Give the admin user or your user full access rights on the mailbox in the exchange management console.
- Allow time to apply setting, mine was instant.
- Log into OWA as the admin user in IE
- On the top right, click the username and open a new mailbox. Type in the user’s email address and click Open.
- It should open for you and you can do what you needed to, including setting up Out of Office, which is what I had to do.