[Davey]

Simple terms: How can a bot authorize an email?
Not possible.
You are placing authorization BEFORE signing up in order to secure your forum being flooded with new registrations.
Users can post straight away (unless you change the permissions to make them very tight).
But the main thing about this hack is authorizing before signing up.
If the user's email is not legitimate, they cannot verify can they?
Therefore they aren't actually added to the database and displayed on the homepage until they have proven themselves.
Get it now?

Dave.

PS:
@Abbas: You said it straight away.
Not everyone can support image verification.
And I cannot, since I am running it on Windows.
But the bottom line is, this has to be a method EVERYONE can use. Otherwise it's not fair.