Exchange 2007 send failures

Are you using DNS to send internet mails or smarthost ?

If DNS, are you able to resolve the mx record and connect to destination smtp server on port 25 ?

If smarthost, are you able to connect to smarthost on port 25 ?

I ma able to resolve the mx record:
nslookup -q=mx gatewayservices.co.za.
Server:  svrdc1.stargazemedia.net
Address:  10.235.4.11

Non-authoritative answer:
gatewayservices.co.za   MX preference = 10, mail exchanger = mail.gatewayservice
s.co.za

mail.gatewayservices.co.za      internet address = 41.203.18.51

i cannot telnet to them on port 25 however:

telnet mail.gatewayservices.co.za 25
Connecting To mail.gatewayservices.co.za...Could not open connection to the host
, on port 25: Connect failed

yes we are using dns to send

Can you please brief about how you send mails to outside/Internet from your organization. (The mail flow) ?

The server where you run telnet is responsible for sending mails to outside ?

Are you able to send mails to some domains or outgoing mails are completely blocked ?

We have an all in one exchange 2007 server.
We have one internet send connector that uses dns to send mail.

Yes the results I gave you are from the server responsible for outside mail.

yes I am able to send to most domains. There is just a handful of domains that I cannot mail to at all.

If the server your trying to send to uses SPF or DKIM to validate sender identities. You could get that error.  Do you have one of those created in DNS under the forward lookup zone for the mail server?

I would suggest you to get in touch with your ISP to check if they have any issues. I have seen such issues before with ISP.

Yes We do.

This is how our primary domain is setup:

stargazemedia.net
A      mail       196.26.201.153                   
A      mail1       196.3.176.128                   
A       @       94.229.169.110                   
A      www       94.229.169.110                   
MX         @       mail1.stargazemedia.net.       10             
TXT       @       v=spf1 mx ~all                   

I have contacted our ISP and they have told me that nothing is wrong on their side.

can you please post few more domains apart from mail.gatewayservices.co.za  ?

I just wanna ensure if there is any pattern i can see.

here you go:
Capture.JPG

Is the PTR record configured to the public IP being used to relay mail.

Sometimes the relay IP is diffrent then mx record IP

to check thruough which IP your exchange is relaying mail send a mail to ipconfirm@postmaster.aol.com
it will respond with the IP thru which your exchange is connecting to internet domains.
And after that check check whether y

there are some troubleshooting tips at aol try this

http://postmaster.aol.com/Postmaster.Troubleshooting.php

Sorry i did not complete my sentence

And after that check check whether your connecting IP has a PTR record.
Many domain doesnt allow emails from IPs which doesn't have PTR record.

And also enter correct fully qualified domain name in send connector properties under general tab in  "Specify the FQDN this connector will provide in response to HELO or EHLO " field.

looks like im still sending through and old IP

How would I correct this relay to reflect to its correct IP adress?

It has to be configured in your local router or network firewall to route the traffic.

Or

ask your ISP where your domain is registered to create an PTR record for the IP which is used for relaying.

any changes on excahnge? Do I need to configure the send connector?
I have changed the FQDN on it from mail.stargazemedia.net to mail1.stargazemedia.net
I have PTR records setup with the ISP so it could be a routing issue...

Looks like the issue was with dual IP's on the NIC the old IP is still routing through our old ISP which was causing mail to be rejected as there ar no longer MX's setup on the old address.

Thanks so much for the assistance.