Emails not working despite using WP SMTP

I am about to give up on WordPress for our ecommerce website.
Email notifications are not working for order placement either to the website or the customers.
We have installed WP SMTP and can receive test messages however no auto emails.
I have been reading that this is a common problem.
Has anyone another solution?
We are with hostpapa and I think that the servers may be a factor.

Any advice would be appreciate before I just leave wordpress and head back to Shopify.