I am developing a Windows Phone app, which needs to make an automatic call when some event occurs, without user interference. Is it possible? (Purpose is legitimate)
If not, is there any other way to send some notification or message to the other phone from my windows phone app?
You can start a PhoneCallTask on Mango or later (so SDK 7.1 and later) – this can be pre-filled, but the action to place the call must be completed by the user of the phone.
Similarly, SMS messaging also requires confirmation (after all, both these actions cost money) – if you need inter-phone communication, you could implement yourself via a webservice and push notifications.