It's Windows Live Messenger for your mobile
It works with :
N72
N73
N80
N91
N92
N93
3250
e50
e60
e61
e70
And maybe more .... just give it a try it's only 232.57 KB
Download:
http://www.ziddu.com/download/1811945/MOBILE-WindowsLive.rar.html
Pass: www.dl4all.com