Useless inscriptions

Hi everybody, I'm a french user of Punbb, so if my english doesn't fit with that I want to explain, so forgive me please, i'll do my best to speak your langage.
It's also my first post here, so I wanted to thank you Rickard, for all the work you did on Punbb, and all the others who have taken part of this project.
Well done !!

Let's talk about my problem now :

Recently, many virtual members have subscribed to my forum punbb, all of them have given an "name_number@my_domain.com" email when registering, conducing to a failure notice : "I'm afraid I wasn't able to deliver your message to the following addresses".

I've read that punbb 1.2.11 fixes DoS attacks, but I'm affraid that it doesn't fixe inscriptions generated by scripts once an IP use.
While I was upgrading my PunBB forum from 1.2.10 to 1.2.11, I wondered if it was possible to oblige the user recognize a "security code" like unidentifiable image by scripts, you see what I mean ? I thought that it was the only way to prevent once a time by IP session, an inscription made by a robot (script).

Does someone know if Rickard plan to care about this problem ?

Thanks for reading me,
Pierrot.