We have just seen hundreds of order confirmations sent out en masse without any action by us. Some go back two or three years. Anyone seen this before and have any advice on how we stop this happening. Only happened once (today) so far.
This is queue method in magento1. Actually it is working one or more customers placed an order at once and system save their order details in DB then after few hours it send the confirmation mail in bulk number. if you don't like this queue method need to remove it by code.