MyBB Community Forums

Someone registered but then forgot to activate their account via email link for a l-oooon-g time. They were just able to view the forums because the permissions were set to allow them to just view and not post.

Then they deleted their registration email.

What should I do?

You can activate it in your ACP ?
ACP - Users and Groups - Search for Users - List Users Awaiting Activation and choose 'Activate' in the DropDown box