Recently we found out that the GP Web Client cannot generate an email with a .pdf document attached (this may be rectified when the Web Client moves to html in GP 2016). Our users still want to use the web client to generate .docx invoices/purchase orders, but really want to be sure that the documents they send out cannot be modified.
To enable password protection on word documents, go to Administration >> Setup >> System >> System Preferences. Mark the check box that says “Protect.docx attachments with a password”. Once that is enabled, customers or vendors will need to enter the password in order to edit the document.
If you don’t send them the password, or have it auto-generated, the recipient cannot easily modify the document.