Access Exchange Server behind NAT

Question

Hello,

We have one server for DC/DNS and another one for Exchange server. Everything is configured and works perfectly.

However, above servers are behind NAT and we have one public IP assigned to us by ISP.

The challenge is how to configure our domain name (mydomain.com) to be able to send/receive email to/from outside our organization.

At the domain registrar we have to configure our authoritative DNS server so I think
ns.mydomain.com
should be glued to the public IP address and then forward port 53 tcp/udp to DNS server. Is that correct and works?

Thanks.

Answer 1

Hello

Thank you for your question and reaching out.

You would need a public domain address to get this up and running, you would also need to configure DNS records for your public domain to point to your exchange server as well.

It is also strongly recommended that is is set up to only use SSL/https, which would involve acquiring an SSL certificate for your exchange server, (if you don't already have one)

• Get any domain name from domain registrar, literally any domain selling website (But i prefer a reputed one).
• Setup MX record in DNS settings in domain hosting by pointing to your public IP address ( you need a static Public IP. if you dont have one, contact your ISP)
• Configure your router to forward all email traffic (port 25) to your internal exchange server ( allow traffic and configure NAT )
• Configure Exchange Server to Send and Receive Outside

Below are Microsoft article and guide to help to access Exchange server outside your Organization.

https://learn.microsoft.com/en-us/exchange/plan-and-deploy/post-installation-tasks/configure-mail-flow-and-client-access?view=exchserver-2019

https://learn.microsoft.com/en-us/exchange/troubleshoot/client-connectivity/set-up-web-access

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Answer 2

Hello,

Thank you but I think forwarding port 25 is not enough and 80, 443, 143, 587 and 110 should also be forwarded. Right?