Hi there, Gengus. 

I know some steps to help you send those customer statements via email.

If you did not receive an error message when creating a statement or if the email simply did not send, we'll need to check some details. To generate a statement, ensure that all preferences are properly selected:
 

• The appropriate customer should be selected.
• The customer should have an invoice or sales receipts within the statement period or before the statement date.
• If the desired customer has a zero balance, under the Do not create statements: the box with a zero balance should be unchecked.

For the Template, select the Intuit Standard Statement. If the Create One Statement is blank, choose Per Customer or Per Job from the drop-down. Also, ensure that the customer has a working email address and that all email preferences are set correctly:

1. Go to the Edit tab, then choose Preferences.
2. Select Send Forms.
3. Check if the email address setup is working, then click OK.

Otherwise, if the email still fails, the issue may be an overflow error. Here's what you need to do:

1. Under the, put a check on the box for with a balance less than.
2. Change the input to 0.00
3. Resend the email.

I also recommend checking this article to learn more about the email service configuration: Connect your email to QuickBooks Desktop.

Return to this thread if you need assistance or have additional questions about customer statements. I'd be happy to help. Keep safe and enjoy the rest of your week.