iPhone: Sending SMS and altering Voicemail message

it is possible 开发者_如何学运维with iphone sdk to send sms to a user or change the voicemail greeting?

thank you

Voicemail greeting: no, you cannot change this from your app.

SMS: limited. You can open a url to the SMS app that start a message to a phone number but cannot actually fill in any message

NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"sms://%@", phoneNumberString]];
[[UIApplication sharedApplication] openURL:url];

This code should launch the Messages app. You cannot send an SMS without leaving the app.

You can however, use 3rd party services that send SMS's for you via the APIs they expose to you. But these would not be sent from the users iPhone like the SMSs they send on their own.