The spamvertised emails contain subjects and messages attempting to socially engineer users into thinking that spam is coming from their mailboxes, and that they face legal action:
In this campaign, emails are spoofed to appear as though they are sent from established companies. The emails even formally claims that legal action will be taken because of the spam you have sent. These emails with the fake warning even attach a ZIP file that contains a scanned copy of a document that is supposed evidence of your spam.
Hello. Your email is sending spam messages. If you don't stop sending spam, we will be impelled to sue you! We've attached a scanned copy of the document assembled by our security service to this letter. Please care carefully read through the document and stop sending spam messages. This is the final warning.