I can see how hard you tried here. No worries, I'll make it up to you to ensure you never have to deal with this again in emailing your invoices in QuickBooks Online (QBO), jwrjfoster.

We can reset your email address to refresh the connection so that you and your customers will receive the emailed invoices. Here's how:

1. Go to Gear icon, then select Account and settings.
2. Go to the Company section, then click Edit ✎ in Contact info.
3. Review each email address and make changes as needed.
4. Click Save, then press Done.

Once done, ask your customers to check their junk mail and spam folders. If the email is still not found, clear and then re-enter your email address. Let me guide you how:

1. Go to Gear icon, then select Account and settings.
2. Go to the Company section, then tap Edit ✎ in Contact info.
3. Clear the Company email field and enter the desired address as is, even if it appears correct. (Be sure not to use any extra characters or spaces before, within, or after the address you enter).
4. Press Save, then Done.
5. Send yourself a test transaction.
6. If you still don't receive the email, try using a different email address that has a different domain (for instance, if you were using a Gmail email address, try a Hotmail or Yahoo address instead).

For more troubleshooting steps option, check out this article: Troubleshoot if customers aren't receiving emails from QuickBooks Online. To help you add, organize, and send invoices, see our Community link for reference: Invoices and payments. It contains related articles on the process.

For your future task, check out this article to learn how to receive invoice payments in QBO. 

I'd like to know how you get on after trying the steps, as I want to ensure this is resolved for you. Please reply to this post and I'll get back to you. Take care always.