iPhone 3Gs iMessage problem

[osxlovers]

My iPhone 3Gs cannot receive or send iMessage even when I configured it correctly on Settings > Messages (added both phone number and email addresses). The message sent from my phone always shown as "Not Delivered". Any suggestions would be appreciated!

iOS: 6.0.1

 

[Jaypi]

Some WiFi networks mess with the activation process used and the phone does not retry. To get your iMessages working,

1) Turn off WiFi
2) Turn ON Cellular Data
3) Turn off iMessage
4) Turn phone off
5) Turn phone on
6) Turn iMessage on
7) Test iMessages
8) Turn WiFi on.

If you do it in that order and allow it to activate over 3G, it works without fail.