[teo_zero]

> the major email providers will penalize you if you generate too many undeliverable emails.

I suspect the rate at which new users may try to create new accounts and type a wrong email address is too low to be noticed by reputation metrics.

[AndroTux]

there's bad actors that use bots to sign up to websites using bogus data.

[teo_zero]

Wait! Are you saying that you process new registration attempts without any rate limit, captcha, etc? Because the moment to filter out (or limit) bad actors is before they submit an email address, not through it.

[AndroTux]

Yeah, good luck with that. Captchas are basically useless in today’s world, so are IP rate limits for anything just a little sophisticated. Of course it helps, but if you think this solves all problems, you live in a dream world.