Websites have a lot of control over referrer headers these days. Often, news aggregators add to urls so the site knows where it came from, or it’s using a feed

Websites have a lot of control over referrer headers these days. Often, news aggregators add to urls so the site knows where it came from, or it’s using a feed that already has that. Now, that said, in an email, you can send links that encode that it’s coming from email, but you would get caught by the non-gmail using people suddenly seeing fake gmail.