INV-72595 reference number provided in the community chat as a known issue that is listed as "Solved" by submitting this reference number

Hi, gatoraquatics.

I appreciate you for letting us know that you're one of the affected users about bounced emails when sending invoices or reminders to customers in QuickBooks Online (QBO) ang sharing some updates about the INV number which is tagged as closed. 

In case you encounter again the same issue, In the meantime, you can use one of the following workarounds to send your invoices:

• You can save your invoice as a PDF and send it via email through your business or other email address.
• You can send your customer a link to their invoice through SMS or messenger service. Simply click on “save and share link” then select “copy link” and paste it into your SMS or messenger service.
• If you have a Gmail or G-suite email account, you can use the send with Gmail feature to send invoices from your address.
• You can save your invoice as a PDF, print it, and send it to your customer via mail.

You can also use this article for other troubleshooting steps in resolving the issue: 3 solutions for you when customers aren't receiving your emails. 

Please get in touch with us again if you have any other queries about managing your invoices in QuickBooks Online. I'm here to help you.