I don't know why but people don't get any e-mail verification after registering.
Does your host allow emails to be sent?
Yeah, I saw It's working but the thing is you get the male after 10 or 20 minutes.
You might want to read this!
http://docs.mybb.com/1.8/faq/mail/
For quick delivery you need to setup SMTP from MyBB settings.
AdminCP --> Settings --> Mail Settings --> Change Mail Handler to SMTP.