Boxbe is an interesting service, thanks. Maybe this 'permission-based' was never a standard because spam didn't exist back then and, later when it did exist, di

Boxbe is an interesting service, thanks. Maybe this 'permission-based' was never a standard because spam didn't exist back then and, later when it did exist, didn't play well with the idea of mailing lists. In the latter context it's funny how this search term is SEO'd to return marketing services! Having just read a former google abuse team member's take on end to end encryption and anti-spam[1], this topic now looks a lot more complex. Regarding IM's, he mentions how spam-free WhatsApp is and argues that spam is a lot easier to fight when you have central control because you can change anything at any time at any point (client or server). [1] Mike Hearn, https://moderncrypto.org/mail-archive/messaging/2014/000780.html https://moderncrypto.org/mail-archive/messaging/2014/000780....