Hello,
Some times our visitors have issues with activation and they contact us to get new codes to validate their accout (mail validation).
Some times people dont write correctly their email addresses and its impossible to correct it, they need to register again !
I am using Invision power board solution for another forum and they have a pretty nice feature, when you register at the end you are logged in but not activated, you stay on a onboarding page where you can request new email (resend), contact ou logout :