Hi Scott! We're so glad to see new users like you actively participating in the Community. You can delete the message, but we suggest checking the mail log first, like the error message says. I have more details about this.
The mail log is a record that tracks the status of emails sent from QuickBooks Online (QBO) Payroll. It can provide information about which emails failed to send, the reasons for failure, and other relevant details that can help you troubleshoot the problem.
If the undelivered emails contain important payroll information, determine if it needs to be resent or addressed. Once done, you can then consider clearing the error message.
Furthermore, you can visit this article to learn more about this year's tax filing schedules: End of Financial Year | FAQ and Resource Hub.
I hope this information about email delivery in QBO Payroll ensures you don't miss any important details while handling it, Scott. We're always here if you encounter error messages when using QuickBooks. Let us know in the comments so we can help you promptly!