Is anyone else having issues with invoices not sending today?

I'm happy to welcome you to the Community. Thanks for reaching out to us by posting your first inquiry in our forum. I'll be sharing information about the email-sending problem in QuickBooks Online. 

We are aware that some QuickBooks Online users are currently experiencing a Delivery Server Down error, preventing them from sending invoices. Our engineers are working diligently to solve this as soon as possible.

Check for any updates regarding the problem, through this link: https://status.quickbooks.intuit.com/.

In the meantime, you can send your invoices manually outside of QuickBooks. To do that:

1. Open your transaction.
2. Click the Print or Preview button.
3. Tap on Download, then save the file.
4. Attach the file to your email, then send it to your customer.

To learn how to personalize and add specific information to your sales forms, please visit this article Customize invoices, estimates, and sales receipts in QuickBooks Online.

We appreciate your understanding and patience. Drop by again if you need further assistance with any QuickBooks-related concerns.  The Community is available 24/7. Keep safe!