E-commerce: Issue with Email Delivery

We have an e-commerce website built with WordPress, and since yesterday we've been experiencing issues with the order confirmation emails. The confirmation emails are no longer being sent to our customers or to us after a new purchase is completed.

We need someone to investigate and resolve this issue as soon as possible, as it is affecting our business operations. This is an urgent request.

Please don't send a proposal if you are not able to resolve this today.