Today I had a request to change an Out of Office reply for a user who incorrectly typed the phone number for the person who was filling in for her. I immediately thought I was going to have to reset the password on the account to do this. But I didn’t.
In order to change the Out of Office Reply you need to have permissions to open that users mailbox. In most cases, the administrator account should have these permissions. That user also needs to have permissions to Outlook Web Access
Open a web browser and navigate to your OWA address. Log on as the administrator. Once you have successfully logged on, in the address bar add the username and “inbox”
Log in as administrator (or with another user who has permissions to open the other mailbox)
Change the url to http://mail.domain.com/Username/Inbox
This takes you to their mailbox
Click on options and change the Out of Office message and save it.
Viola! You changed it without having to reset the users password.