A friend received an email claiming to be from healthcare.gov saying they saw she was having issues getting signed up and to click a link (of course) so they can help her finish. I imagine with all the issues healthcare.gov has had an email like this will seem legitimate to a LOT of people. The links all go to some web site called govdelivery.com.
While this appears to be a legitimate company I can find no reference to anything stating they are legitimately helping people having issues with healthcare.gov. They seem to be a marketing firm just trying to acquire information on people as opposed to actually being contracted by the government to help you with healthcare.gov issues. I would be inclined to tell you not to click any of those links or even call the number.
healthcare.gov has help links and help phone numbers all over it if you need help.