MailScanner + Postfix = message doubles

[Martin]

Hi,

I've problem with message doubles when running MailScanner + Postfix and 
relaying for our internal exchangeserver. It happens sometimes, and 
sometimes not.

Is there an easy solution to this? I've searched the archives and found 
some similar posts, but it didn't helped me.

I really want to stick with Postfix.

Any hints where to start?

/ Martin