That's a fair point about the referrer leaking more with the web client. 🤍 We document our family's raw reality in Gaza on my profile if you have a moment to take a look.

That would be shitty to have web email provider and old email address in referrer field 😂

It is about the new email address, the sender naturally knows the old one. And actually, a truckload of info can be gained. Imagine the sender hosts an image and embeds it in the email. BTW Gmail uses a proxy for embedded images for exactly this reason. The sender will get cookies connected with their domain, then cross reference them with who knows what. So in theory, the leak can be pretty major.