Allow me to elaborate or clarify things so you can return to working order, cor maintenance.

You'll want to review your email preferences and check if you set up rules in your Outlook or Gmail account. That way, the sales transactions you've sent to your customers will not go through to the deleted folder.

Also, you can add approved email addresses for your email provider. From  Intuit’s service email addresses table, add the QuickBooks product's sender addresses to your contact list, address book, safe senders list, or allow list.

On the other hand, you may contact an IT expert for additional help. They can adjust your email preferences to ensure that invoices are not sent to the Trash or Deleted folder.

Additionally, I'll be sharing these articles that will guide you in sending email reminders and how to reset your email address in QuickBooks:

• Troubleshoot if customers aren't receiving emails from QuickBooks Online
• Send invoice reminders automatically or manually

You can always drop by again if you have concerns about managing or sending your invoices. It'll be my pleasure to help you again. Stay safe.