Hi,I'm running Windows W2003 SP2, Exchange 2003 SP2. I have setup my domain as domain.local but have a domain hosted by ISP with .com.au. My issue is that intermittently people sending mail to me get a timeout bounce back stating my mail server is not contactable, yet I receive other mail fine on that same day. I use a smart host, and my DNS is setup to only forward. My MX record points to my server but it is not part of the .com.au namespace, it is called server.domain.local. Could this be my problem? Can anyone shed some light? I included the .com.au domain in the Internet Message Formats in System Manager.Thanks in advance

HI Lorale,You said other receive other mails on the same day and have problem with intermittently people.Those users are belong to same email domain or from diffrent domains ?Please check with you ISP wathear that domain blocked ?regards Chinthaka Shameera | MCITP: EA | MCSE: M | http://ExchangeShare.WordPress.com

Hi, You need to change your MX records from Domain.Local to Domain.Com.Au. Its invalid on internet and as Chinthaka asked, can you update that the mails are you receiving belong to the same domain or a different domain from internet? Thanks.Vishal Ramnani | MCITP - Exchange 2007 | MCSE Messaging | MCTS - Win 2008 Config

The senders are from different domains, not always the same domains get the error.

I realise domain.local is invalid on the internet, but this is not going out to the internet. The namespace .local is for internal use only. This is a valid setup as described by Microsoft to keep namespace separate for security puposes.

My MX record points to my server but it is not part of the .com.au namespace, it is called server.domain.local. How come u registered a MX record with server.domain.local?be a little bit clear on your issue, to troubleshoot...and to understand...

I thought I needed an MX record on this server so router knows where to send mail. I don't seem to be able to setup the MX record to show the .com.au domain, even as a CNAME. Can you help me do this, if this is what I need to do?

Hey, Please note that MX records are the records on public DNS to route messages from INternet to your incoming SMTP Server. This article will give you a very good insight on MX Records, its standards, how and where to setup etc. http://www.petri.co.il/configure_mx_records_for_incoming_smtp_email_traffic.htm THanks. Vishal Ramnani | MCITP - Exchange 2007 | MCSE Messaging | MCTS - Win 2008 Config

hey,I realise what MX records are, but thank you anyway for the article. I have read the article, to give you more of an understanding to my problem, I fit in the paragraph titled'internal network' where I need to consult a network specialist to see whether configuring an MX record will do harm or not - hence my question in this forum.I have a public IP address only on my router, this IP is the MX record that my ISP has the mail going to. I do not have a public ip address for my server. I haveport forwarding for port 25 going to my server from the router. I thought I would need to have an MX record on my server so that the router would know where to send it. My internal DNS server is configured to forward all requests apart from internal network to ISP DNS. Should I create a new zone on my internal DNS with my .com.au namespace. I have not done this in the belief that it would confuse the DNS server as to where to send requests. I set up the two different namespace as recommended by Microsoft for security purposes to keep them separate.Thanks

For a better understanding, i'll just brief your setup now.. Correct me if i'm wrong.. You have and internal AD Domain called as "Domain.Local" In this Domain you have one Mail server by the Name "Server".... FQDN= Server.Domain.Local (Is your Exchange Server with Private IP) Perimeter Level you have one Router which has a Global IP (Ex: 201.2.1.2) This Global IP is natted to your internal Exchange server with port Rules enabled that is 25. You have an official Public SMTP Domain Name (Domain.Com.au) regsitered with Domain registra and they have created a A Record, MX record on their DNS server. The MX record points to the Global IP (201.2.1.2) which is on your Router. **Comment**(Confirm me does your MX record resolves to your IP 201.2.1.2) Internal Mails are routed through a Smart host. If the above points are correct then there is no issue with your Exchange Infrastructure setup...... (Its a recommended architecture for SMB) Dont create any Zones on your internal DNS servers... Configuration is correct... Your Internal DNS server's resolve External Domain names from your ISP's DNS servers... (ISP DNS server IP's are specified in the Forwarders of your DNS server properties). Now the issue is, there's a delay in external mails comming to your domain...... There could be 2 issues 1. There could be a Problem with your Router configuration 2. There could be a problem with your ISP who has given the Public IP (Leased Line) Check This........ NSLOOKUP > set q=mx > domain.com.au Server: resolver1.ispdnservername.com Address: 20.20.20.20 Non-authoritative answer: Domain.com.au MX preference = 10, mail exchanger = mx1.Domain.com.au mx1.Domain.com.au internet address = 201.2.1.2 Hari This posting is provided "AS IS" with no warranties, and confirms no rights.

As i understood that you have only one IP on your Router and you have enabled forwarding of packets coming on port 25 (NATTING), Then i would suggest you just change the MX record which is on ISPs DNS server and add a SMTP Address with that Domain in Recipient Policies. Create/Change MX Record with the name "Domain.Com.Au" which should point to "Server.Domain.Com.Au" (Preference could be anything e.g. 1 - 10) and create a A (host) Record named "Server.Domain.Com.Au" as to be resolved as the public IP address you have on Router. Next step would be to add a secondary SMTP address to accept mail on "Domain.Com.Au". make that primary if required. follow this article for details. http://www.petri.co.il/configure_exchange_2000_2003_to_receive_email_for_other_domains.htm I hope this helps. ThanksVishal Ramnani | MCITP - Exchange 2007 | MCSE Messaging | MCTS - Win 2008 Config

Hi,Thanks for your reply. Yes, you are correct in your statements. Only one question, I was under the impression that internal mails would be resolved by my internal DNS server and only external mail would be forwarded to the smart host. When I run nslookup as you suggested, my resolving server is my internal server, the non-authoritative server is my ISP's DNS server, but in answer to your question, yes my MX record on ISP points to my router.Thanks for your time