Question : Exchange SMTP connector AUTH rejection

This seems a little odd.

In SBS20003, the SMTP connector has been told to forward email via another server (linux box)
The outbound security is set to basic auth with the correct user name and password set.

The queue status information on this connector states "The remote SMTP service rejected the AUTH negotiation".   I know that normally means the user name or password is not set correctly.  I KNOW the user name and password is set correctly, because I have set additional debug information in the linux mail log that shows me both the connection coming in, along with the username and password being used and confirms that the connection has been accepted.

Yet the Exchange connector still insists that the AUTH negotiation was rejected.

Two questions:
1. Could exchange be incorrectly reporting this error.
2. Is there further debugging information available in the SBS2003  box that may allow me to see more detail of the connection from the Windows end.

There may be a clue in the error message - the NEGOTIATION was rejected rather than password.  Don't know how fine grained the connector reporting would be.

Thanks
SF

Answer : Exchange SMTP connector AUTH rejection

Just a wild stab in the dark here, but could the issue be on your linux box?
Something like maybe it limits the number of emails it will accept during a given time?