You can view the email history of an Invoice through both the Web Portal and the App.
From the Web Portal > CRM Invoices > search invoice with filters to see the last emailed column
or
From the Web Portal > edit / select the Invoice > Scroll down to the History/Notes. This will show all manual and automated emails that have been sent relating to this Invoice as well as edit history.
From within the App > accounts > invoices > select the invoice that you would like to view > history.
