Proton, the Swiss company that develops privacy-focused online services such as email, has developed its very own CAPTCHA service to help discern between
Capchas are often hidden, only bothering the user when they're not suspected to be a human. Popularity might also play a role. I've personally never heard of Runbox, maybe they're not big enough to attract bots? Also possible that they're a paid email provider?
Capchas are often hidden, only bothering the user when they're not suspected to be a human. Popularity might also play a role. I've personally never heard of Runbox, maybe they're not big enough to attract bots? Also possible that they're a paid email provider?