Changed ISP providers and external ip address

Exchange 2000


  • 1. Internal and Extarnal DNS name for Exhange5.5
    I has Exchange5.5 server behind ISA firewall. In Internet my mail server has name, but in local network it has name (myHOMEdomain is virtual, is not registered in Internet) When I send mail to Internet the server in header of mail write and some of mail servers does not receive our mail because error: 450 <>: Helo command rejected: Host not found What can I do ? How change server name that it write in all message to Internet ?
  • 2. How do I configure the front end to be an smtp gateway?
    I have an exchange 2003 front end server in the DMZ and a 2003 Back end server. The front end is only being used for OWA. The Back end has an smtp connector to the Internet and processes all inbound and outbound mail. I want to move this function to the Front end. I want to configure the front end so that all incoming mail goes to it (i know i have to change my mx record) and the front end sends it to the mailbox on the back end. This setup would also require the back end to send in outbound mail to the front end for delivery. Is there any good doc on how to set this up?
  • 3. SMTP Connector in SBS2k3
    I am having trouble sending mail to and addresses from all PC's in the network all running XP Pro sp1 & outlook 2k3. I am running SBS 2003 premium will all critical updates. When we send a message we can see it in the SMTP Queues. the message sits in the SmallBusiness SMTP connector - (aol connector) Protocol SMTP Soruce Default SMTP virual server State Retry We have no trouble sending or recieving any other domains, earthlink says they are not blocking and the users are not blocking the messages. Is it us?

Changed ISP providers and external ip address

Postby Um9vaw » Sun, 20 Nov 2005 02:22:07 GMT

I have an exchange server that we moved from another building to a new one.  
We had to change ISP providers and get a new external ip address.  What needs 
to be done to set up with the new ISP provider and the new external ip 
address?  Do I change the MX record and A record to point to new external ip 
address?  Is this right and what else might I do.  Do I have to change any 
setting on the exchange server itself?  Thanks

Re: Changed ISP providers and external ip address

Postby Bharat Suneja » Sun, 20 Nov 2005 03:00:44 GMT

Your Exchange server's most likely using internal/private IP addresses - if 
that's the case, as long as your internal IP addressing is the same (in your 
new building), you don't need to change anything on your server.
- DNS: Yes, A record should map to new external IP address, no change 
required in MX - it points to the A record.
- Firewall: If you're using a firewall/NAT, you'll need to make changes to 
the IP addresses and NAT rule(s) on the fw.
Bharat Suneja

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2.External IP Address Change

Prior to a network change we used NAT (public/private IP addresses) in our 
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reverse DNS pointer record.

We switched to port forwarding in our router. All NAT is gone. The problem: 
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Is Exchange aware of the public ip in this scenario? Should I just change 
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3.Change of External IP address


We are moving premises at the weekend and I need to sort out out email.

We currenlty run Exchange 2007 and have an MX record pointed to our external 
IP address. When we move, we will be allocated a new IP address (ISP can not 
move IP address!). We will also be waiting a few days for our new ADSL 
service to be up and running. 

What options do we have so we can still use our exchange server to continue 
receiving email?

Any help would be appreciated.

Many thanks,


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I suspect DNS, so I added my DNS IP addresses provided from my DSL 
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