Hello there, @yogiana5.
Access to emailing invoices and other add-on services will be unavailable once QuickBooks has reached its 3-year product life cycle.
It would be best to upgrade the product if you're using any of the QBDT offered features.
You can visit this article to know more about the QuickBooks Desktop service discontinuation (Disco) policy and upgrade information.
Here's the link to the price list of the QuickBooks Desktop version 2018:
If you need anything else, feel free to let me know.
