David Mackintosh wrote: > R Lists06 wrote: > >> Have you considered changing your setup to reject emails in the smtp >> process >> if they do not have a valid rcpt to? i.e. a valid email address on your >> machine to accept them? >> >> This will eliminate much of what you are experiencing... > > Well I'm willing to consider it. The problem is that the 'primary' MX > for most of the inbound-relayed domains is a barracuda anti-spam device > which talks to a Exchange server through a secret-handshake pipe I can't > get at from the secondary. > you can do regular pulls of valid email addresses from the Exchange box to your seconday. People have protected Exchange with postfix for example.