I think you should set up a DNS server to serve the LAN/DMZ with the 
proper MX records of the internal ip of the mail servers.

Cheers
Raylund

Spectra wrote:

>"It is not possible to access NATed services using the WAN IP address from
>within LAN (or an optional network)."
>
>This has become a huge headache for us.
>
>We have two email servers on our dmz.  both are running axentra software,
>version 2.4.  Both servers can send and receive emails from any email
>server on the internet with the exception of each other, because the two
>servers are on the same network.  currently we have the dns forwarder
>enabled (using the internal ip addresses of the servers), so both servers
>should be able to 'see' each other via the internal ip.
>
>however, emails cannot be sent or received between the two servers.
>
>interestingly enough, the axentra software has an override that allows for
>the use of an external smtp server.  setting this to some smtp server
>outside our network allows for the sending and receiving of emails.
>
>does this sound like a dns or smtp issue?
>
>has anyone else had a similar problem?
>
>what have you done to overcome this?
>
>i hope i'm being clear enough; let me know if this is confusing.
>
>  
>