New order mail not being sent

If emails are enabled and orders are updating to Processing, there could be an issue in the email delivery to a recipient. This could be a spam blocker that classified your emails are spam and stopped them. Installing a mail logging plugin can help here.

Install WP Mail Logging plugin. This will log all outgoing mails so you can see what is being sent. Once installed:

Generate a test order
Go to your admin dashboard > WP Mail Log
See if your test order generated emails, and if there are any sending errors reported

If the email was sent, but not received, the best way to resolve this is to sign up for an account with a dedicated SMTP provider (an average site can usually stay within free usage accounts that are available) which will send the email for you. This should be more reliable than your own servers mail sending functions.

Question as well, did you actually setup POST SMTP? A lot of times, I have seen people just enable the plugin without actually setting it up. This “appears” to work but as Amanda stated they can get flagged as spam.

And other mails are working like expected (i.e invoice, reset password, products not in stock)

When I send it manually (from the back-end) it works as well.

If the emails are not automatically triggered but are received when you manually send them, it could indicate a plugin/theme customization conflict. You might have a piece of code hooked improperly into a WooCommerce order status change action which prevents the rest of the code hooked into that action from firing.

We haven’t heard back from you in a while, so I’m going to mark this as resolved – if you have any further questions, you can start a new thread.