Over the last 24 hours, I have also been experiencing the same email duplication problem. This has happened when sending Invoice Reminders, Estimates, and Invoices. I have no recurring transactions. I have been using QBO for nearly 3 years for two different companies and have not experienced this problem in the past. I have made no changes to my operating conditions - continue to use a Chrome browser, same computer, etc. A couple of customers were confused by receiving two emails, thinking they were different, then realizing both had the same information.