In Essentials you can add an attachment to an Invoice when emailing it to a client. What would be fantastic is to be able to View the attachement in Essentials afterwards.
A good example of this is client who specialises in Homekill butchery gets a document from their client on how they want the processing done. They will then attach a copy of the document to the email to the client.
When reviewing the invoice it would greatly improve the workflow to be able to view the emailed attachement.