> -----Original Message----- > From: Peter [mailto:peter at vardus.com] > > Can an email client send an HTTP referrer when you click a > link? Does an email client send HTTP headers? > And: HTTP referrers get sent > by the browser in the headers, right?? HTTP_REFERER (spelled incorrectly in the standard) is sent from a browser in the headers when you click through from one page to the next. If you type a URL directly, the REFERER is sent as blank. When you click on a link in most e-mail clients, on Windows at least, it will open your browser and automatically enter the URL in the Address bar. Because of that, the only headers that will be sent are the ones that are normally sent when you type the URL in manually. It will send headers, but the HTTP_REFERER will be blank. I'm not sure if there are any mail clients that could get around this and convince the browser to send a REFERER in the header. One workaround, if you control both the e-mail and the website, is to add a flag to the query string. The link in the e-mail would read http://yourserver.com/newsletter0901.htm?email=True. Then your page could check the value of 'email' rather than checking the HTTP_REFERER.