SASL AUTH LOGIN became mad !

Hello,

I have à big problem with cyrus and libsasl2-login on Mandrake 9.2.
We tried to use SMTP with sasl authentication. We installed
libbsasl2-plain and libsasl2-login (for outlook).
All was ok until we found some LARGE mail queue.

In fact, it's very simple to bypass authentication and create an open
relay. Strange :-(

Example :

[scollado@zeus scollado]$ telnet myserveur 25
Trying XXX.XXX.XXX.XXX...
Connected to myserveur
Escape character is \'^]\'.
220 myserver
EHLO toto.com
250-myserveur
250-PIPELINING
250-SIZE 10240000
250-ETRN
250-AUTH DIGEST-MD5 CRAM-MD5 LOGIN PLAIN
250-AUTH=DIGEST-MD5 CRAM-MD5 LOGIN PLAIN
250 8BITMIME
AUTH LOGIN
334 VXNlcm5hbWU6
hello
334 UGFzc3dvcmQ6
UGFzc3dvcmQ6
235 Authentication successful

We tried to rebuild your own library but nothing changed !
Could you help me?

Thank you