I normally add that IP into my spf, and create another mx record for it. Shouldn't matter because it will never respond on 25/smtp but its in the dns config .
From: Don Andrews [mailto:[EMAIL PROTECTED] Sent: Thursday, January 10, 2008 12:18 PM To: MS-Exchange Admin Issues Subject: RE: IP addresses different Yes, as long as you have a PTR or reverse lookup record pointing to the IP your mail comes from. _____ From: David Mazzaccaro [mailto:[EMAIL PROTECTED] Sent: Thursday, January 10, 2008 7:35 AM To: MS-Exchange Admin Issues Subject: IP addresses different Hi all, I have 5 public IP addresses from my ISP. One of them is x.x.x.A which is assigned to the outside interface of my firewall. Another one is x.x.x.B and is the static mapping for SMTP to my Exchange server. So, when we send outgoing email, the return path is shown as x.x.x.A (the outside interface of our firewall). However, our MX record is configured in DNS to go to x.x.x.B so incoming email hits x.x.x.B and then the firewall maps that to 192.168.x.x (our Exchange server) Is this setup ok? (i.e. is it ok to have a different sending IP than a receiving one?) -Dave ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~
