AUDIENCE: Administrators, Marketing Users
When a recipient replies to your Act-On email message, the reply is sent to the 'From' address you specified when you created the message, unless you have specified a different 'Reply to' address.
Out of office notifications are generally handled differently than replies. If your recipient is out of the office, it is up to the recipient's email server to send the notification back to the 'From' address or the 'Reply to' address. Most often, they will send it to the 'From' address.