email sending using drupal 7

You can use drupal_mail() function to send an email from Drupal site. Search for this function on different forums on this site and you will get an answer.

Thanks,

You should learn to search for drupal modules.

(drupal module library search)
https://www.drupal.org/project/project_module?f%5B0%5D=&f%5B1%5D=&f%5B2%...

(google search)
https://www.google.com/search?num=100&q=mail+module+site%3Adrupal.org

https://www.drupal.org/project/mailsystem

https://www.drupal.org/project/htmlmail

https://www.drupal.org/project/simple_mail

https://www.drupal.org/project/mimemail

Hi,
There are lots of modules as per told above you should go for it,but if you are new to drupal then you can also use the built in php send mail without using drupal functions:

like;
function contact_form_submit($form, &$form_state) {
to=$user->mail;
$subject="";
$headers="mail-id";
$message="your message here";
$sentmail = mail($to,$subject,$message,$headers);
}
It might help you.