Duplicate, mail remove (?)

[Medina]

Hello,

I hope that this is the right section to ask my question.
Its about the following issue. Id like to have a check at duplicate registerd mail addresses in my admincp. And that by the check i can remove the duplicated (lets say the oldest members stay the new one have to register a new mail address.

Is this modification already available? And if it is - please give me a link to it.

Thank you,
Mr_Virtual