Link to home
Start Free TrialLog in
Avatar of stevengrimshaw
stevengrimshawFlag for South Africa

asked on

Step by Step Guide Routing Mail

To Support

I need a step by step guide to setting up Exchange to route Mail Through Exchange DNS and explain Reverse DNS.
I normally just use the ISP's smtp settings and Pop Conector but now have a router that won't allow this, so I need my SBS Server to recieve and send out the Email through DNS.
I have a static IP on the SBS Server.

Thanks
Avatar of DocCan11
DocCan11

quick question before I give you a detail answer.. what version of exchange are you using on your SBS and is this what you want to setup to deliver the mail?
Avatar of stevengrimshaw

ASKER

Exchange Version 6.5 sevice pack 2, and Yes ...
Actually you are using Exchange 2003.. I have one last question and this pertains to HOW you want the mail delivered.. you have two choices and my answer will depend on which you choose.. Do you want the Exchange server to deliver  the mail directly or do you want your Exchange server to deliver the mail to your ISP's mail server for delivery? It should be the last question I ask you before telling you how.
Hi Doc

Hmmmm can you explain both, Pretty please with a cherry on top.

Thanks
ok.. lets first address what needs to be done to allow you to receive email.. I would assume at present you have a registered domain name on the internet and that you are hosting your email on the ISP mail server.. so first thig you will need to do is change the mx record in your dns zone to point to your SBS.. now if you are using NAT you will need to point the mx record to the IP address of your router (you would be using NAT if your SBS does not have a valid internet IP address that was assigned to you by your ISP) The mx record is what other mail servers look for when they try and find how to deliver mail to your domain..

If your router IS using NAT to allow your network to get onto internet you will need to configure the router to forward traffic on port 25 (smtp) to your SBS. I you are not using NAT you will need to configure your router to open port 25 (you may want to create a rule that only allows forwarding to your SBS server for better security).

This should allow you to receive email from the internet but will not allow you to send quite yet.. I need to get going to work but I will try and find time today to continue this answer.
I am at work now so I can finish this discussion.. The next thing you need to do is configure your Exchange server to deliver mail out.. There are two possible solutions as I mentioned earlier..

Sol'n 1: Direct delivery
In this solution you will allow your exchange server to contact each domain directly to deliver the mail.. Open exchange system manager and then on the left side choose connectors.. you will probably not have any connectors configured (this is normal).. Right click in the right screen and choose new, SMTP connector (exchange uses connectors to deliver mail and smtp virtual servers to receive mail).. Give the connector a friendly name like Internet,  it should have selected as default the choice "Use DNS to route to each address space on this connector", this will allow the server to do a DNS lookup for each mail domain it needs to contact to find the mx record so it can directly contact those servers to deliver the mail. ( the only requirement is your SBS server MUST have a DNS server configured that is able to communicate with the internet!). Next click on the Address Space tab, click Add, choose SMTP, click OK then leave the default domain name of "*". You are now able to send email to the internet.. you can play with the other tabs if you like to do things like control how much data is sent in a single connection but it is not necessary to have mail flow.

sol'n 2: Forward all mail to your ISP for delivery:
The solution for this is almost the same as above, the only difference is when you first create the connector on the General tab you will change the radio button to "Forward all mail through this connector to the following smart host". In the box below you will fill in the FQDN of your ISP's mail server.  Now all mail leaving your organization will be delivered to the ISP mail server and they will take car of delivering it for you..

That now allow mail delivery.. Make sure of course your firewall allows SMTP traffic (TCP prot 25) to flow through..

The last question you asked about was reverse DNS.. Originally DNS was designed to only convert a name to an IP address. It was decided they needed something to do the reverse, take an IP address and convert it to a DNS name.. This is what DNS reverse lookup does.. It is configured on DNS by creating a reverse lookup zone. A reverse lookup zone is populated with PTRrecords (the point to an A or host record). One of the ways this is used is to check that a mail server is who it says it is.. When a mail server starts to send you mail from a domain you can check that in fact the IP address it is using is from the domain it says.
I hope this explanation helps.. I was typing it quickly if you need any clarification just post and I will clarify for you ..
Thanks For all your help, I will get into trying all of the above and If I have any quetions I will ask for Your divine intervention as and when I need it, oh holy one...
ASKER CERTIFIED SOLUTION
Avatar of DocCan11
DocCan11

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Avatar of Jeffrey Kane - TechSoEasy
Jeffrey Kane - TechSoEasy
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial