If we need to send email only when transaction number is updated and not order shipped or completed email. Please follow the below steps.

1. Visit WooCommerce Settings Page


2. Click Emails Tab

3. Below screenshot refers to the two emails which are sent

  1. When notes are updated with Transaction Number

  2. Order is Shipped / Completed

Click Gear icon next to Complete Order Email

4.  Disable the Notification

Once you disable the notification, you will only get email when a tracking number is attached to a Order