Hi Wietse, I had a look at the links that you've suggested me. If I've understand correctly, I don't have to use the 'smtpd_sender_restrictions' option, because I have to match the receiver and, if it's in transport_maps = proxy:mysql:/etc/postfix/mysql-virtual_transports.cf, then means that it's internal and don't need to be in queue.
So I guess I need to use the option 'smtpd_recipient_restrictions' At the moment it is that option: smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination So now I think I've to modify it, so that I'll tell that if the receiver is matching with an address of transport_maps (Internal email), then nothing, otherwhise put all the emails in HOLD. This is the theory. But pratically how the smtpd_recipient_restrictions should look like? Thanks Michele
