Once you upgrade to Magento 1.9 from an earlier version, you will encounter a common problem; when the order is placed, the new order confirmation email cannot be sent. In Magento 1.9, the manner in which the new order confirmation email is sent will be different (from the previous versions of Magento). In this version, Magento will be sending the confirmation emails in the queue. This method will be followed instead of sending those emails immediately after the customer places an order after fix the Magento order email not sending issue.
However, you can try to make it work as it did in the earlier versions of Magento. To perform this task, follow the steps provided below:
The above method should fix the Magento Order Email Not Sending issue.