Subject: mail template design is your problem, possible.
When you say the OOO is sending notification for emails earlier then when it was turned on, are they the same day or prior to the day the agent is activated? It wasn’t until version 8 or 8.5 that you could control the time of day when you wanted the OOO to start. So if you turn on the agent at 4PM it will respond to all emails received prior to that time on that day. Updating your mail design and ODS are the required ways to take advantage of the newer features.
Yes, it is responding to all emails on that day, sometimes earlier.
Unfortunately, we cannot upgrade the mail-template to 8.x at the moment. We’re using a third party product which does not yet support 8.x mail templates (if we do upgrade now, it’ll break the the 3rd party product).
Looks like I’ll have to suggest the option of switching the agent’s trigger to “on event” and “after new email has arrived”.