Drupal Bug Fix

Hi there I have a bug fix on my website where the contact form is showing this error when an message is submitted •Notice: Undefined property: stdClass::$mail in contact_personal_form_submit() (line 283 of /home/****/public_html/modules/contact/[login to view URL]). •Unable to send e-mail. Contact the site administrator if the problem persists. and this error when a user signs up for an account: •Unable to send e-mail. Contact the site administrator if the problem persists. •Unable to send e-mail. Contact the site administrator if the problem persists Please only quote if you are extremely experienced with Drupal and PHP. If this project is completed quickly I will have more work for you. Thanks Jenny