We are not receiving email alerts once a client processes a payment, how can I turn this function back on?

Thanks for posting here, @thaskins007,

You'd want to make sure that the payment notification email delivery is set in the Account and Settings page within QuickBooks. Let me guide you on how to do that.

1. Login to your QuickBooks Online account.
2. Go to the Gear icon then Account and Settings.
3. Tap the Company menu.
4. Scroll down to the Contact info section.
5. Click the Pencil icon to edit your email address. 
6. Pick the Save button.
7. Press Done.

Also, make sure to update your contact information in the Merchant Service Center:

1. Log in to your QuickBooks Payments account.
2. From the menu, select Account, then Account Profile.
3. Go to the Contact Information section, then select Edit.
4. Change your contact information as desired, then select Save.

There are different email addresses associated with your Payments account. Each one receives different kinds of messages, such as:

• News about your account goes to your Contact Email. This address also appears on your receipts.
• Account access messages go to your Intuit Account Email.
• Statement or deposit alerts go to individual email address destinations you set for each alert type.

If you need further assistance with this, please post here again so I can help you further. Have a good one!