The only people who would register would be janitors, mods, and admins. There are 4chan passes where you pay $20 a year to skip captchas and have a lower post cooldown which works by associating a token with an IP address. The token is emailed to you and you get reminder emails when the token is expiring so you can renew it. So 4chan would likely have emails for pass users too. Pass users still post anonymously. I don’t know the exact stat but I remember the owner saying something like only 1% of users have a pass.
Even bigger question: why would you register on 4chan? Isn’t the whole point anonymity?
The only people who would register would be janitors, mods, and admins. There are 4chan passes where you pay $20 a year to skip captchas and have a lower post cooldown which works by associating a token with an IP address. The token is emailed to you and you get reminder emails when the token is expiring so you can renew it. So 4chan would likely have emails for pass users too. Pass users still post anonymously. I don’t know the exact stat but I remember the owner saying something like only 1% of users have a pass.