[Mimedefang] one last error

[Weyland]

I'm not sure if this is a MD or SA problem, so if someone could 
give me just a pointer in the right direction, I'd appreciate it.

I've gotten everything else fixed, but run into this last one - 

When using sendmail configured without MD/SA, everything's fine.
As soon as I configure it with MD/SA I am unable 
to send mail from another box to the MAILBOX.

The error I'm getting from Outlook Express is this - 


The message could not be sent because the server rejected the sender's e-mail 
address. The sender's e-mail address was 'nw2linux at varangiankindred.org'. 
Subject 'Fw: Testing for MD/SA integration', Account: 'Weyland's test 
account', Server: '192.168.1.2', Protocol: SMTP, Server Response: '451 4.7.1 
Please try again later', Port: 25, Secure(SSL): No, Server Error: 451, Error 
Number: 0x800CCC78

Thanks for your help,

Weyland