test and check dns settings

1) check the DNS server setting on the exchange server and make sure it is pointing to the correct AD/DNS server
2) Check the exchange server's ip address in the DNS server (under Fwd lookup & Reverse Lookup Zones), if you cannot find. Go back to the exchange server and run the command  "IPCONFIG /REGISTERDNS"
3) Wait for sometimes and check the DNS server again under "forward Lookup zones" and "Reverse Lookup zones" for the exchange server entry
4) If the exchange server entry is not their in the DNS, you can add the DNS entry (A) record manually in the DNS server with PRT record.

Also make sure the gateway IP address on the exchange server is right and check whether you can able to access the internet from the exchange server, if you allowed. This is to confirm the internet communcation wtih outside is ok.

dnsreport.com redirects to dnsstuff.  the dns tools if for google.com, etc  cant seem to put in my domain.  i have changed firewall settings and tested ports for incoming mail.  all ok.
also noticed when i nslookup on dns server it get the error *** Can't find server name... / Default Server:
i have checked reverse dns lookup and its correct.  strange.

the error i get when sending an email to anyone in  the domain is  This message is looping: it already has my Delivered-To line. (#5.4.6)

and it looks like this is coming from my secondary mail server.  an external host

1. exchange server is pointing to correct dns server
2. exchange server is not the dns server.  should there be a fwd entry for the exchange server on the dns server??
gateway ip is correct and can get internet on exchange server.

i just noticed if i nslookup on both servers they respond correctly.  registerdns may have corrected this.

hi Rick,

R u doing the nslookup from the local DNS server? Is your DNS server is Active Directory Integrated DNS server?

vsganesh.  yes to all

Yes, looks like your exchange server is not registered with DNS earlier after you change the IP address of the exchange server.

After your did the registerdns and now you can able to do the nslookup.

Is the email looping error gone now?

i sent an test email.  just waiting for either a bounce back or delivery.  has been 1min or so now.  usually the bouncebacks were quick to come back.  will let you know as soon as i get something

yes still have looping error :(

have restarted all exchange service? if not, restart it.

yeh i have already.  

its seems the mail isnt even getting to the exchange server.

i have a pop email account setup for that exchage and it checks mail fine.  the exchange responds to pop requests.  just cannot seem to send from external account to the domain.  loop error, bounce back from secondary mail host.  

1) It looks like you can send/recieve email internally, rite?
2) R u able to send email to external email accounts?
3) R u able to telnet port 25 to your email server's public IP address from external?
4) How many MX records configured for your email domain in the Public DNS server?
5) Is all MX records pointing to the correct public IP address and that public IP address mapped to your exchange server's private IP in the firewall?

1.yes
2.yes
3.yes
4  two.  1 pointing to exchange server, 2nd pointing to previous mail host
5. yes

strange i know!!!

What is the MX preference configured for both servers in the pubic DNS server?

10 exchange server
30 secondary

1) Is your previous mail host still live?
2) Is your previous mail host is also the exchange server?
3) do you have any SMTP connector configured between previous mail hosts and the exchange server?

Also do the telnet port 25 to the exchange from external and send the test email via telnet. Check whether you can receive that email?

It looks like there is looping between previous mail host and the exchange server.

1. some mail account still exist at previous mail host
2. previous mail host is an email hosting company who used to host our mail.  now we host our own
3. no, not anymore

i get the error "unimplemented 5.5.1 error"
just to clarify.  i am at home, my work is having the issues
teletn myhomeisp mail server 25
mail from: my home account@.....
rcpt to: myproblemwork account@.........
.
 etc
this is obviously testing mail sent into work (the problem) from my isp.

1) Do the telnet port 25 to the exchange from external and send the test email via telnet. Check whether you can receive that email?

2) Can you confirm your MX record? Is it like this?
10 exchange server (exchange server public IP addres)
30 mail host (ISP mail host IP address)

3) It looks like your incoming email from external is getting rejected from the secondary host which is in the ISP.  R u able to see any SMTP traffic coming in the firewall? Send the test email from external and check the firewall logs

1. done got the error "unimplemented 5.5.1 error"
2. yes.  exactly
3. dont think so but will double check now

No, do the telnet in the following way.

1) telnet yourwork email server's public IP  25 (the IP which is mentioned in the MX record for the exchange in the public DNS server)
2) mail from: my homeaccount@...
3) rcpt to: myproblemwork account@....
etc...

no logs in firewall for blocking mail.

when i telnet i dont even get a chance to type in helo, it goes straight back to c:\docs&setts. as soon as i press a key

yeh cannot telnet to work from any location.  its like it doesnt respond properly.
as i said as soon as i type helo after the first key it drops off.

ok, the SMTP connection  from external to to your exchange is not happening...

1) check the Port 25 is opened in the firewall
2) check the public ip address is nat (static nat) to the exchagne server internal IP address
3) check the "Default SMTP virutal server" settings under access control, connection control and relay restriction. let me know the current settings.
4) Also do the telnet port 25 to the exchange from internally and make sure it works

rebooted the firewall.  
i just noticed now when telnet 25 it is dropping the connection.  and logging in the firewall.
i will delete the port fwd rule and resetup.  and see if it passes thru

forget that last post.  i have the port fwd disabled.    argh

The rules should be like this in the firewall:

1) Static Nat:  Public IP address to Exchange internal IP addres
2) Rules:  Source -> Any  and  Target -> Public IP address
3) Port: 25

ohhh.."port fwd disabled" may cause this issue..:) cose it is forwarding the SMTP packets from public IP to internal IP address.

Hope you have reached the solution :)

no same issue.  i know how the rule of the fwall should be set.
everything was all set before.  all that changed was the internal network range.
the firewall has the correct ports open and is fwding to the correct servers.
telnet is still an issue though.  cant get a proper response but have no blocked logs.

ill keep looking at this tomorrow.  thanks so far

1) R u able to telnet to the exchange server from internally?
2) Do you have any connection restriction in the exchange server under "Default SMTP server" -> Properties-> Access -> Connection Control
3) Is your exchange server pointing to this firewall for the gateway?
4) If the above are ok, then something do with firewall.

Is their any restriction or block from firewall to the exchange server? Does the firewall can response back to the exchange server? or another host in the internal/applications (if any)?

Ok...good luck