Hi all, we use the Postini for our MX records. Now, we have external web site which use the web hosts' SMTP server that users (which are senders' email addresses )requested the info. If any sender with external email address instead of mycompany.com, mails are received. If any sender with our email address with mycompany.com to request the info, the messages got bounced back right away. I guess that if mails from our domain mycompany.com originated from web host's SMTP server and is delivered to Postini and Postini rejects which states it does not like that IP, Why? Thank you.

Are you also using Postini as an outbound mail relay for your Exchange servers?[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

No. through another SMTP server. Thank you.

Do you have the IP addresses of these web host mail servers added to your SPF records?[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

>Do you have the IP addresses of these web host mail servers added to your SPF records? No. as the from address is fake non-exist doamin.

It sounds like Postini is protecting you from email that appears to have a high potential for being spam, by virtue of having a From: address in a fake domain. Sending email from a fake domain is bad practice to start with.[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

thank you. just curious:we whitelist the host's IP.

That's a question for Postini.[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "