What email addresses and domains should I ask our customers to whitelist? All of a sudden, they are not receiving emailed estimates and invoices. Not in junk or spam.

Let’s resolve the email delivery issue so you can receive your payments on time, Jocelyn. 
 

Here are key service email addresses your customers can mark as a safe sender to ensure they receive important communications from QuickBooks:

 

You can share this article with your customers so they can add Intuit domains to their contact list: Receive important email messages from Intuit.

As an additional step, you can clear and re-enter the email address to ensure invoices and estimates reach your customers. This is particularly helpful if the emails aren’t in their spam or junk folders.
 

If the same thing occurs, consult an IT expert to add QBO's mail server hostnames and IP addresses to your email server's allowlist. The steps vary by email setup. Refer to this article for the required hostnames and IP addresses: Troubleshoot if customers aren't receiving emails from QuickBooks Online. 

On top of that, you can send your invoices and estimates using your personal email or a different domain.

If you have further questions about sales transactions or QuickBooks tasks, reach out through the Community space.