I'm still fighting spam bots. I removed the bio for folks without a hubwheel. The bio was their dumping ground. Fucking spammers. Going to China very soon. Do me a solid and search your spam folder for hubski emails. If you find one, label it "not spam". Let me know if you find one. :)
Would you mind if I made a suggestion? I took a look at your math problems, and to risk sounding like an idiot, I doubt I could solve them without just copying and pasting them into Google. Which, if Google could figure it out, a bot probably could. I can answer word problems though, such as . . . "What's three sevens, ten times over?" 210 I doubt a bot could read that, let alone answer it, but the math would be much more accessible for people.
I found a handful! Good luck with the whole convincing-google-you-aren't-spamming thing. I don't know if it fits your use case, but I've had good luck with using amazon's simple email service for sending email verification emails and notifications and whatnot. it is ridiculously cheap -- you get x,xxx free a month or something so i don't think i've ever paid for it. sometimes it's nice to just make that bit someone else's problem :)
Actually, I didn't receive any emails (responses, shout-outs, badges) from Hubski since 4th of June. Didn't change settings (send everything), email address (gmail btw) or anything else. And I mean didn't receive anything. It's not even in the spam folder. If you need any data I can post them here or send them via mail.