MS Exchange and RDNS problems

HI All

I have a FRUSTRATING problem i cant seem to get rid of.

ENVIRONMENT:
Corporate Win 2003 server running MS Exchange.

PROBLEM:
From within my dev/staging lab we want to test sending emails from our "invite a friend" email notification loop. That dev/staging server has an internal IP addy 10.11.6.75. It has a NAT on the load Balancer (F5 BigIP) that NATS 10.11.6.75 to 12.70.145.35.

In any event you fill out the "email a friend" form and the internal dev/stage webserver sends the email to the exchange server, BUT when the exchange server receives the email IMF automatically puts the message in the SPAM queue (the client never sees the message).

I looked through the headers and the only thing i can see that might cause the problem is a line where it says RDNS failed:

Received: from 10.11.6.75 ([12.70.145.35] RDNS failed) by mail.hyperpia.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 6 Nov 2008 13:17:27 -0800

I have tried:
adding

1. adding a PTR record in DNS reverse lookup zone in the 10.11.6.x subnet
2. adding a PTR record in DNS reverse lookup zone in the 12.70.145.x subnet
3. adding an A record in DNS reverse lookup zone in the 10.11.6.x subnet
4. adding a A record in DNS reverse lookup zone in the 12.70.145.x subnet
5. Went into the ESM, global settings, message delivery, message delivery properties and added the following IP's to the Global Accept and Deny list 10.11.6.75 & 12.70.145.35
6. added an exception to the the list to block service rules

and yet I STILL cannot receive these email tests?!?!?

any suggestions?????

Sounds like you need to go to ESM -> SMTP Properties -> Delivery Tab -> Advanced and make sure you have mail.hyperpia.com in the FQDN field.

Then call whoever hosts 12.70.145.35 and have them put a RDNS back to it.