Over the last few weeks my quotes

Let's perform some troubleshooting steps for your customers received 

the invoices, @raybuild4-bigpon.

I've checked here on our end and there's no reported issue where customers not receiving emailed transactions. Let's ask your customers to check their junk mail or spam folders if the sent emails are routed to those locations.

If the email is still not found, let's try clearing re-entering your email address to refresh it in QuickBooks Online (QBO). Here's how:

1. Go to the Gear icon on the top menu.

2. Under Your Company, select Account and Settings.

3. In the Contact info section, tap Email.

4. Clear the Company email field and enter the desired address, even if it appears correct as is. Let's make sure not to use any extra characters or spaces before, within, or after the address, you enter. 

5. Press Save and then Done.

Then, try sending yourself a test transaction again. If you still don't receive the email, try using a different email address that has a different domain (for instance, if you were using a Gmail email address, try a Hotmail or Yahoo address instead.

If the same thing happens, we may need to configure the server to accept QuickBooks Online mail server hostnames and IP addresses. Just follow Solution 3 for when customers aren't receiving your email. You can also contact your IT expert to have the QBO mail server hostnames and IP addresses are added to your outgoing mail servers.

Feel free to visit our Sales transactions page for more insights about adding and managing customer invoices, sales receipts, and other sales forms.

I'd like to know how you get on after trying the steps, as I want to ensure this is resolved for you. Please reply to this post and I'll get back to you. Take care always.