Forcing users to replace Fake real email

[yeku]

How can I force my old users to place a real email?

sorry for my english

thanks

[medicalforums]

Go to admincp>notices>
Add a new notice that to be shown only to users registered before / - / - /

Tell them in the notice that they have to upate their email, or otherwise you'll kill them :D:D (just joking)