Too much spam -> some changes/blacklisting

[mean]

The spam / dummy registrations are getting too high
That's causing problem with the hosting company that has some automatic triggers for failing emails etc...

As a result :
1- whole domains were blacklisted : mmmmail / mailinator / hotmail. They are used by spammers/robots a lot. Please use another one.
2- registration now needs to be manually approve and you 'll not receive a welcome email