PiWik not showing Referrer websites

When I check the referrer websites widget, it is actually not showing real referrer websites, and instead shows something like the below screenshot. Our website is an elgg based social network. The widget was properly working 6 months ago. And I am unable to fix this, can anyone please help?

Anyone here to help please?

These “Referrer websites” are actually visitors coming from their webmail

Yes, around 6 months ago, it actually showed external webpages as well. Any idea how to fix this?