Steve wrote:
It seems a bit convoluted by my guess would be to set up two main.cf files, the seconds (short) version denying everything and then get cron to swap these in and out at the required times. I guess, doing it this way, I can set some exemptions and white listing in the second conf.
Why bother with special configs? Just stop postfix at 0:00 and start it again at 7:00. Legitimate mail will queue up at the senders' MTAs and come in when your server comes back up.