https://www.vice.com/en_us/article/m7ajqa/us-says-iran-behind-threatening-voter-emails

The U.S. government accused Iran of being behind the recent threatening emails sent to several voters in Florida, Arizona, and Alaska during a press conference on Wednesday. 

The Director of National Intelligence John Ratcliffe said that the emails, which were designed to make it look like they came from the far-right group Proud Boys, were "desperate attempts by desperate adversaries.”