WPESignature gives you the option to automatically attach a PDF of the signed document to the confirmation email that is sent to the signer(s), document creator, and any CC'd users.
To set up this feature, navigate to eSignature > Add-ons > find Attach PDF to Email > enable > find Save as PDF > enable.
Once both add-ons are enabled, edit your document > select Send a PDF of this agreement as an email attachment in the Document Options > publish.
After completing these steps, the final PDF will be added as an attachment to all confirmation emails as soon as the document is closed. 👍