[Exim] PAM problem / smtp auth

Hi all,

I'm trying to get SMTP authentication working on my freebsd-server,
but I just can't get it to work. I've searched the maillist and
google several times but without any result.

The problem is this:

I've added the following lines to my configure file:
plain:
driver = plaintext
public_name = PLAIN
server_condition = "${if pam{$2:$3}{1}{0}}"
server_set_id = $2

login:
driver = plaintext
public_name = LOGIN
server_prompts = "Username:: : Password::"
server_condition = "${if pam{$1:$2}{1}{0}}"
server_set_id = $1

When I try to login, I get "535 Incorrect authentication data" error
although the username and password are correct. I've runed exim with
debug level on 10 and this is the result:

250-SIZE 31457280
250-PIPELINING
250-AUTH PLAIN LOGIN
250 HELP
SMTP<< AUTH LOGIN
SMTP>> 334 VXNlcm5hbWU6
SMTP>> 334 UGFzc3dvcmQ6
Running PAM authentication for user "hoststar"
PAM error: Authentication failure
login authenticator:
$1 = hoststar
$2 = <correct_password>
expanded string: 0
SMTP>> 535 Incorrect authentication data

Does anyone know what I'm doing wrong? By the way I haven't put
anything special in my /etc/pam.conf is this neccesary? If so what do
I need to put into it.

Thanx in advance,