I appreciate you posting your QuickBooks Desktop email verification concern here in the community, ChereeLutz. Let me share further information regarding this topic.
To begin with, could you please specify which transaction you are attempting to confirm the emailed date for in your QuickBooks Desktop (QBDT)? Providing these details will enable me to offer a personalized and effective solution to address your inquiry.
Furthermore, if you're trying to verify the date of an invoice sent via email, you can do so by utilizing the See History feature on the invoice page. I'll be leaving a screenshot as your virtual reference.

Moreover, I agree with BigRedConsulting's statement that the most recent date displayed in the email history corresponds to the date the email was sent.
After sending out your invoices, you’ll begin receiving payments from your customers. You can refer to this article to document those payments: Record an invoice payment.
Let me know if you need additional help verifying your QBDT email date. I'll be ready to assist as soon as I receive your response.