On Sat, 12 Apr 2014, Reindl Harald wrote:
nonsense - there are so much ISP nameservers broken out there responding with wildcards and so on that you can not trust them and you will realize that if not before after you started to run a production mailserver which relies on NXDOMAIN responses for proper operations
That's not what the http://atlas.ripe.net/ data set indicates. Your story seems anecdotal and incidental.
Yes, there are a few bad players out there (like Rogers in Canada) but those are in a minority. That said, I agree that using unbound on your servers will reduce upstream DNS outage problems on your servers. I wouldn't run unbound on every VM though.
Paul