Hillary Clinton isn’t the only one who may have had an e-mail security problem. A security researcher has discovered that the Trump Organization’s mail servers all run on a version of Microsoft Windows Server that has been out of support for years, with minimal user security. The e-mail servers for Trump’s hotels, golf courses and other businesses run on an unpatched version of Windows Server 2003 with Internet Information Server 6—making them a vulnerable target for anyone who might want to gain access to the organization’s e-mails.

Security researcher Kevin Beaumont posted the finding on Twitter at 6:00pm on Monday: