Listen outgoing SMS or sent box in Android

Basically, you have to register a content observer… something like this:

ContentResolver contentResolver = context.getContentResolver();
contentResolver.registerContentObserver(Uri.parse("content://sms/out"),true, yourObserver);

yourObserver is an object (new YourObserver(new Handler())) that could look like this:

class YourObserver extends ContentObserver {

    public YourObserver(Handler handler) {
        super(handler);
    }

    @Override
    public void onChange(boolean selfChange) {
        super.onChange(selfChange);
        // save the message to the SD card here
    }
}

So, how exactly do you get the content of the SMS? You must use a Cursor:

// save the message to the SD card here
Uri uriSMSURI = Uri.parse("content://sms/out");
Cursor cur = this.getContentResolver().query(uriSMSURI, null, null, null, null);
 // this will make it point to the first record, which is the last SMS sent
cur.moveToNext();
String content = cur.getString(cur.getColumnIndex("body"));
// use cur.getColumnNames() to get a list of all available columns...
// each field that compounds a SMS is represented by a column (phone number, status, etc.)
// then just save all data you want to the SDcard :)