edit this code to use a site email and not a user email PHPFOX

so i have this social network script called phpfox and the invite button doesn't work because they send the email via the logged in users email and the server rejects it.

I believe this is the code that sends the email

 /**
 *
 * @param string $sMail email of the invited person
 * @param integer $iInviter user who invited $sMail
 * @return integer id of the new insert
 */
public function addInvite($sMail, $iInviter)
{
    return $this->database()->insert($this->_sTable, [
            'user_id' => (int)$iInviter,
            'email' => $sMail,
            'time_stamp' => PHPFOX_TIME,
            'is_used' => 0
        ]
    );
}

how can i edit this so when the email is sent its sent from admin@mydomian.com