Some emails are currently being caught in an outgoing spam filter. This is problematic for two reasons:
Obviously, you're not getting the email.
The system thinks the email went through, which can put it into a weird state.
For the first problem, I've added an SPF entry to my DNS settings. Supposedly this will help with not being marked spam, but it takes some time for DNS changes to propagate.
For the second problem, I will look into ways of detecting when the outgoing spam filter is triggered.
So what this means for now is that if you don't receive your email (check YOUR spam folder first) within 15 minutes or so, try re-requesting. I've seen the first re-request go through for one person and then 5 re-requests all fail for someone else, so YMMV.