iMessage not activating

[Mach2001]

Not sure if I am just being dumb, do I need to be connected to wi-fi to turn imessage on or should it activate automatically as I am trying over 3g and it just says 'Verifying' and then tells me there has been an error.

 

[Collin789]

It should activate on either one.

 

[Arelunde]

Do you have iMessage turned on in Settings > Messages? Also in the same setting location, do you have you iPhone set to receive iMessages on your phone number AND email? That might make a difference.