Lab Setup for ESA not working

[muhammad_2013331]

(Internal DNS Server/Exchange Server) -----DMZ----(Cisco ASA)----Outside----(External DNS Server/hMail Server)

My internal DNS Server is in domain internal.com and external DNS server in external.com. I can send mail from/to Exchange/hMail servers within the same domain, but what I want to do is, I want to send mail from internal.com to external.com and back.

For this i have done the following tasks:

1. Have made a conditional forwarder to Public Address of internal.com DNS Server
2. Conditional forwarder to external.com domain on internal.com DNS Server

All NAT is correct, even i can connect on SMTP port of Exchange server from Outside, and similarly from inside. Both DNS Servers have respetive MX Records for email servers in their respective domains. But i am still not able to send email from internal.com to external.com and back.

Any help will be appreciated.

[Libin Varghese]

I would suggest looking at mail_logs on the ESA as a start to see if the connection reaches the ESA (logged as ICID) and then working from there based on what/if any errors are observed.

Regards,

Libin Varghese

[muhammad_2013331]

I have not yet introduced Cisco ESA in the midst, just two SMTP/POP/IMAP Servers(hmail and Exchange) are not able to exchange mail from different domains.

[Libin Varghese]

You may want to reach out to Microsoft support forums for help with any logs you see when sending emails between the exchange servers.

Once you have ESA passing the emails through it, we can certainly help further.

Regards,

Libin