Hi,
Like bestlux said the pin 2 of board is not free pin so you cannot use pin 2 for DHT sensor. So you need to change this line of code:
</s><i>
</i>#define DHTPIN 2 // what pin we're connected to
<e>
Second thing temperature and humidity data is in float to first you need to covert float value to char Array. Try this solution.
</s><i>
</i>float temperature = 25;
char smtp[30];
String temp = String(temperature);
temp.toCharArray(buf , temp.length()+1);
<e>
I hope it will help you.