Within your customer profile, under the Invoices section you will now find an activity feed for both payments and or email delivery.
Payment Activity Feed:
The payment activity feed will detail payments collected, reversed and or transferred
Email Activity Feed:
Processed indicates "sent"
Please wait 1-2 minutes after sending the email for the delivery status to appear within the activity feed (we also recommend refreshing the page)
A deferred email indicates that the email could not be delivered
If the email is listed as Opened, this indicates the customer has viewed the invoice.