Cannot send out invoices. message in red - need attention. error message - quick books cannot make contact with e-mail addresses on invoice. already checked - correct?

Hello there, @claudette5. I want to ensure you'll be able to send invoices in QuickBooks Online (QBO). 

Thanks for sharing the details of your issue. Currently, we have an ongoing issue related to being unable to send invoices, however, the error message that other customers getting is the delivery error. Since you've verified that the email address is correct and you're having a different error, we can perform the following steps to fix it.

Let's begin by accessing your account via an incognito browser to have a clean slate. Below are the shortcut keys you can use:

• Google Chrome: press Ctrl + Shift + N
• Mozilla Firefox: press Ctrl + Shift + P
• Microsoft Edge: press Ctrl + Shift + P
• Safari: press Command + Shift +N

Once signed in, send the invoice again. If this works, go back to your regular browser and clear the cache to eliminate the piled-up data that may cause an issue when delivering the form. If the same error persists, you can use a mobile device and data to send the transaction.

In case you're still unable to, let's now try to send them to your email or em_t2@intuit.com. From there, check if you still encounter the same error. 

However, if none of the steps above works for you, I highly suggest reaching out to our Phone support team to further investigate the root cause of the issue. They can also create a ticket for this if necessary. 

As a workaround, you can export the invoice to Excel or PDF and manually send it to your customers outside the program. 

You can also personalise your invoices by adding a custom logo, changing column widths, etc. for the detailed steps, check this article: Customise invoices, estimates, and sales receipts in QuickBooks Online.

I'd be happy to provide additional steps if you have any other concerns about sending invoices in QuickBooks. Please don't hesitate to leave a reply below. Have a good one and stay safe.