Found an email cap I'll probably never hit, and I'm paying to remove it anyway

I'm a week or so out from launching this, and I was doing a pass over the infrastructure when I found something worth knowing.

Resend's free plan advertises 3,000 a month, but the number that actually binds is 100 a day. Every signup sends two of those, a confirmation and then a welcome, so in practice it comes out to about 50 signups in a day.

I'm not expecting anywhere near 50 signups in a day, so the ceiling itself isn't really the problem. What got my attention is that going over it fails in the background. Nothing queues, the send just gets rejected and the email never goes out, and paying later doesn't flush the backlog. My welcome email happens to survive that, because it only gets marked sent after a success and retries on the next login, but the confirmation has no such fallback. Without a confirmation there's no login, so someone ends up with an account they can't get into and nobody is notified.

So the risk isn't hitting the limit, it's that if I ever do, I won't find out about it, and whoever it happened to just quietly leaves.

$20/month prevents that, which seems like an easy trade. Anyway, worth checking the daily number on your free tier rather than the monthly one.