Question : My email are being rejected at some location.

I am using exchange 2007, and my mx record are located in godaddy.com
when  my user sent out email some of the meails get rejected, I called my isp to see if they had something to do with it, and they said no because they are not hosting the dns for the company. To call GoDaddy. I called today and they told to configure the dns section under my domain, but they could not give me instruction on how to do it. Can someone send me step by step instructions on how to configure the ptr record for my domain to point to my exchange server so the emails won't get rejected?

This is a example of an email of one of my user
This message has not yet been delivered. Microsoft Exchange will continue to try delivering the message on your behalf.

Delivery of this message will be attempted until 8/20/2010 4:11:26 PM (GMT-05:00) Eastern Time (US & Canada). Microsoft Exchange will notify you if the message can't be delivered by that time.
sample number 2
Your message wasn't delivered because of security policies. Microsoft Exchange will not try to redeliver this message for you. Please provide the following diagnostic text to your system administrator.
The following organization rejected your message: webmail.readytek.com.

Generating server: PRESSRV.prescafe.local

[email protected]
webmail.readytek.com #501 5.7.1 <[email protected]m>... Sender IP must resolve ##

Answer : My email are being rejected at some location.

OK. lets go right back to basics.
1. please confirm IP address is set on NIC and server can ping itself
2. please confirm windows firewall is disabled
3. I think the DHCP error is a red herring - ignore it for now
4. Network cards do fail. Does the server have another NIC in it already that you can make active? if not can you buy one?   - make sure you take the IP settings off the old NIC first
5. have you swapped the LAN cable and plugged into new port on the switch?

That will do for now