My invoices are showing as not sent when they have been sent , what is the problem ?

Thank you for posting here in the Community, @Janefownes.

I'd like to share some details about the email delivery issue you're experiencing in QuickBooks. 

Currently, there's an ongoing investigation for invoices that shows undeliverable when they have been sent. Our engineering team have been working on a fix, that will allow the transaction status to change from UNDELIVERED to DELIVERED/SENT.

To link your account to the list of affected users, I recommend reaching out to our Customer Care team. This way, you'll be able to get updates about the issue as well as if the resolution is available. 

 Here's how:

1. Click the Help menu in the upper-right hand corner and click Talk to a human.
2. Type in "Talk to a human", then press Enter.
3. Look for I still need a human and click it.
4. Select Get help from a human.
5. Choose between Chat with us, Schedule an appointment, or Have us call you.

You can also visit our support hours page to ensure you'll be assisted on time. 

In the meantime, while the fix is being worked on, let's download the invoices and send them to your clients manually using your email provider outside QuickBooks. 

1. Go to the Sales tab, then click Invoices.
2. Check the invoices you want to download.
3. Click the Batch actions button, then select Print.
4. On the PDF preview screen, click the Download button.
5. Save the invoices as PDF, then use your email provider and send them to your clients. 

If you want to send a single invoice, simply open it in QuickBooks. Then click the Print or Preview button. On the previous window, click the Download button to save it as a PDF. 

Just in case you want to personalize your sales forms to reflect more of your business identity, customising the template you use in QBO is a breeze.

We appreciate your patience as we're working to bring the email delivery back to normal. If you have any other concerns with QuickBooks, let us know, and we'll help you out.