Well, they give you both options--smart host and private DNS--and then give you several reasons why they believe private DNS is better. So, that's why I went that route.
Good point on the NAT suggestion... I had forgotten that this server has two NICs. One has a public IP address, and that's the one that outbound mail is routed through (I can confirm this by looking at message headers). The other NIC has a NAT address. When I go to the web, traffic is routed through that one (I can confirm this by going to whatismyip.com). So now I'm wondering... I know which NIC/IP is used for sending mail, but I can't say for sure which NIC/IP Exchange uses for DNS resolution when looking to a private DNS server... -----Original Message----- From: Ben Scott [mailto:mailvor...@gmail.com] Sent: Monday, June 08, 2009 9:44 AM To: MS-Exchange Admin Issues Subject: Re: Exchange 2007 & Postini On Mon, Jun 8, 2009 at 9:33 AM, John Hornbuckle<john.hornbuc...@taylor.k12.fl.us> wrote: > I'm using the private DNS method, where you configure Exchange to use > a specific DNS server to resolve addresses for messages bound for > the outside world. Ewww. They can't let you just configure an SMTP "smart host" to receive all your outbound mail? That would seem to be a lot less disgusting. > For kicks, I dropped to a command prompt on my server and ran nslookup, > pointing it to Postini's DNS server. I was able to connect, but not resolve > any > host names. Every time I tried, I got a "query refused" message. Sounds like this is more of a DNS issue than an Exchange issue. But anyway, their nameservers are prolly configured to only accept queries from known IP addresses (i.e., their customers). The queries issued from your Exchange box are apparently not coming from an IP address they expect. Looks for NAT, firewall, proxy, etc., devices between your Exchange box and the rest of the world. Chances are your DNS queries aren't coming from where you think they are. -- Ben ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~ ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~
