[Spambayes] trained with smtp proxy

[Poudrerie de Luxembourg SA]

Sirs,

We installed spambayes version 1.0a9 on windows 2000 SP4. We received mail via spambayes in our Exchange 2000. This part is working fine and Spambayes do a good filtering of the spam.
We would like to train our database by bouncing back mail via smtp proxy (so each user can trained the system). It doesn't work. All the mail forwarded back is kept in the Exchange queue, as Exchange the smtp proxy of Spambayes seems to refuse the mails.. We try to connect to Spambayes with telnet to send a message and receive almost every time a 550 unkown user when we send a RCPT TO:useraddres. Is it a known problem with our version ?
If we had to install the new release 1.0rc1, how must we do it to not loose all our parameters and training database ?

Thank you in advance for your help

Best regards,

E. Lacoste