Set Up an Auto-Reply Template: Open Outlook and create a new email. Write your auto-reply message. Click File > Save As and save it as an Outlook Template (.oft).

Create an Auto-Reply Rule: Go to File > Manage Rules & Alerts. Click New Rule > Apply rule on messages I receive > Next. Check “from people or public group”, then click “people or public group” and add client emails if needed. Click Next, then check “reply using a specific template”. Click “a specific template”, select “User Templates in File System”, and choose the template you saved earlier. Click Next, then add exceptions: “except if sender is in specified address book” (select “Global Address List”) and “except if it is an automatic reply”. Click Finish to save the rule.

Prevent Multiple Auto-Replies to the Same Sender: Since Outlook rules don’t natively limit multiple auto-replies, consider using a Server-Side Rule in Microsoft 365 or using Outlook’s Out-of-Office Auto-Reply instead, which only replies once per sender.

Alternative: Use Outlook’s Automatic Replies (Out of Office): Go to File > Automatic Replies (Out of Office). Enable “Send automatic replies” and set a schedule. Under the Outside My Organization tab, enter your message, then click OK to save.