This one has me stumped. One of the contacts that I send email to regularly says he gets a warning message every time he opens my email saying there is an ActiveX Controls is trying to run. He only gets that message from my emails. I am running Windows 7, Thunderbird email client, Firefox browser, Microsft Security Essentials, and have run CCleaner and Spybot. I don't use IE or Outlook. My email server is set up for IMAP and the SMTP goes through 1and1.com, which I have set up control on. Any suggestions? Is it on my end or his end? Should I worry about it?