Hello there, @neverred. 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).

I'll gladly share the update of the said investigation and guide you with some workarounds so you can send your invoices and manage customer transactions in QBO accordingly.

For the time being, based on our records, the investigation about bounced emails when sending invoices or reminders to customers in QBO is still open and in progress. Rest assured that this issue is being taken care of with utmost urgency. Hopefully, you can send your invoices and reminders in no time.

In the meantime, you can follow any of the workarounds below so you can send invoices:

• Save your invoice as a PDF and send it via email through your business or other email address.
• 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 own address.
• Save your invoice as a PDF, print it, and send it to your customer via mail.

In line with this, I'd recommend contacting our Customer Care team. They can add your account to the list of affected users. This ensures you're in the loop about the investigation's status and its fix. You can provide INV-72595 as your reference. Here's how:

1. Sign in to your QBO company.
2. Go to the Help (?) menu.
3. Select the Search tab.
4. Click the Contact Us button.
5. Enter a brief description of your concern in the What can we help you with? field.
6. Select Continue.
7. Choose a way to connect with us (Send a message or Get a callback).

Once everything is all set, you may also want to check out one of our Help pages as your reference to guide you in managing and customizing invoices using QBO: Organize invoices and payments for QuickBooks Online. 

We appreciate your patience regarding this matter. Please keep me posted on how it goes in the comments below. If you have other concerns about managing invoices and payment transactions in QBO, I'm always ready to help. Take care, and I wish you continued success, @neverred.