I'm running into a really frustrating problem since installing Mountain Lion. The Messages app, which I've been looking forward to since trying the beta version in Lion, isn't working for me with iMessage. I get the following message when I start the app: And then this in the accounts window: Clicking 'Resend verification email' does nothing - I get no email! Clicking 'Remove Email' also does nothing, the dialogue just re-presents itself. Anyone experienced a similar issue? I really want to get this working!