Hello, when I pay an invoice the 'paid' invoice is normally sent via email. This used to work, but now does not. If I create and invoice or resend, the inv is received.

Hi there, @PaulHolmes. I've got here steps to ensure you'll be able to receive the emailed invoice in QuickBooks Online (QBO).

There are several ways how you can resolve this. To start, you can reset the email address entered in the program if you've recently imported QuickBooks Desktop data into your QBO account. To do so, simply go to the Account and settings page and clear and re-enter the information. Here's how:

1. In your QBO company, select Account and settings.
2. Next, go to the Company tab and click the Contact info section.
3. From there, clear the Company email address field and enter the desired address, even if you see that it's the correct one. Ensure not to use any extra characters or spaces before, within, or after the address, you enter.
4. Then, select Save and click Done.

Another way is to reach out to an IT expert to help you add the QBO mail server hostnames and IP addresses to your outgoing mail servers. These steps can easily be perform on your end. 

Lastly, you'll want to use a different email address with a different domain in sending the invoice.

For reference, feel free to open this article: 3 solutions for you when customers aren't receiving your emails.

Please let me know how this goes. I'd love to hear updates about this. If you have additional questions about emailing invoices in QBO, feel free to leave a comment below. I'm always around in the Community to lend a hand. Have a good one and take care.