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Cannot send e-mail messages to a particular domain

I think I have a rather tough e-mail, routing or exchange server question.  

A freind of mine has an office building with two businesses in it.  The two businesses are sharing some of their network infrastructure but maintain two different Windows domains.  One of the businesses I will call "G" and the other I shall call "M".  

In a nutshell, "M" can not send e-mail messages to "G."   "M" can send e-mail messages to almost anywhere but "G".  "G" on the other hand can send e-mail to "M" with no difficulty.  Below is my attempt at a network schematic...

                                                         WEB
                                                           |
                                                           |
                                                           |
                                                    Cisco 2600
                                                           |
                                                           |
                              ===========================
                             |                            |                              |
                             |                            |                              |
                             |                            |                              |
                       "G" SBServer       "G" Cisco 800                "M" Cisco 2600
                             |                            |                              |
                             |                            |                              |
                       SWITCH ------------------|                              |------------------- SWITCH
                      |  |     |                                                                                   |  |    |
                      |  |     |                                                                                   |  |    |
                      |  |     |                                                                                   |  |    |            
                      O O    O                                                                                   O O   Windows 2K Term Server



I can send mail to anywhere from "M" but not the Excange server in the Gallagher domain.  Anyone have some insight into what could be wrong?
0
Gary Gordon
Asked:
Gary Gordon
  • 2
1 Solution
 
nitadminCommented:
Are you getting any NDRs? (non-delivery reports).
Do you have Exchange running on Both Servers, G SBServer and Windows 2k Term Server?
Are these two servers in different subnets?
Are these two servers Domain Controller?
Are these two servers in two Separate Active Directory Domains?
Do you have to separate DNS servers?

Cheers,
NITADMIN
0
 
SembeeCommented:
This is probably a DNS issue.
The MX records for the other domain will resolve to an external IP address, which you will not be able to connect to because they share the same network.

Easiest way round this is to create a DNS zone for the other domain in each Windows domain. Create hosts for www, ftp etc that point at the relevant external IP addresses (ping www.domain.com before creating the zone to see what address it is).
Then create a host of mail.domain.com and point it at the internal IP address of the other server and then create an MX record pointing at that host. Remember that MX records cannot be IP addresses, but a host.

Repeat for the other domain to come back to the first one.

This is effectively a split DNS system but for the other domain.

Simon.
0
 
nitadminCommented:
Do an telenet test on smtp port, also do portqry command too.

http://www.petri.co.il/smtp_pop3_and_telnet.htm
http://www.petri.co.il/quickly_find_remote_open_ports.htm


Cheers,
NITADMIN
0
 
Ehab SalemIT ManagerCommented:
Do you have a publishing rule on the 2600 for both servers? do both servers have published IPs? Are both receiving emails from the outside world?

It looks to me as either an access-list issue on the M 2600 or a routing problem.

I suggest to enable logging on both of the 2600 and trace for the lost mail errors.
0

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