$fromName = $_POST['username'];
$fromEmail = $_POST['email'];
$theMessage = $_POST['message'];
$theSubject = $_POST['subject'];

$mail = new PHPMailer;

$mail->isSMTP();
$mail->Host = 'smtp.hosts.co';
$mail->SMTPAuth = true;
$mail->Username = 'username';
$mail->Password = '.........';

$mail->From = 'person@ourcompany.com';
$mail->FromName = 'ourcompany';
$mail->addAddress('support@ourcompany.com', 'ourcompany');
$mail->addReplyTo($fromEmail, $fromName);

$mail->Subject = $theSubject;
$mail->Body    = "<p>You have got a email from <b>{$fromName}<{$fromEmail}></b></p>";
$mail->Body    .= "<p><b>The actual message is given bellow</b></p>";
$mail->Body    .= "<p>";
$mail->Body    .= nl2br($theMessage);
$mail->Body    .= "</p>";

$mail->From = 'person@ourcompany.com';

$fromName = $_POST['username'];

You have got a email from sendername<sender@gmail.com>
The actual message is given bellow
Hi,.........................