How to configure a dns and an email server on windows 7

I used Simple DNS Plus and Quick ‘n Easy Mail Server - note that both are not free software but you can try them in trial mode.
You will also need and EML file viewer because the emails are saved as .eml files.
Get FREE EML File Viewer from here

They are very strait forward to configure.
In Simple DNS Plus - Select Records and add a Primary zome.
Then add in your zone an MX-record and make some inquiry to see if everything is ok.

To check if your mail server dns settings are good, open a cmd and make an inquiry :

nslookup -q=mx mydomain.com 

         (uses your isp or local dns server to resolve)

nslookup -q=mx mydomain.com 8.8.8.8 

(using specified Google dns server 8.8.8.8 to interrogate for our domain - I recommend this as it is almost instant update)

To check local open port on your system/server use CurrPorts if you want a Gui or netstat

For dns you have to open port 53
For email you have to open ports : 25,110

You have to port forward ports 53, 25, 110 if you have a router.

You can use this site to check if your ports are open : http://tagclouds.ro/openports.php

 Additional information :

To clear dns cash in windows in cmd type : ipconfig /flushdns
To see in browser new changes made to dns change your dns to 8.8.8.8 ( google dns)