# Setting up hMailServer as internal mail server

Did you ever wanted to have an internal mail server so you can setup and test your Phishing infrastructure? I got you here!

If you prefer the video version of this documentation, including live debugging, feel welcomed:

My environment looks like this:

Here, the lsec.local domain is inside a dedicated Active Directory and network managed by the PFSense firewall and yes, everything is virtualized from the PC. I did not want to shoot up a new server just for mail purposes (mainly because of resources) but rather use one of the DCs. In this case, DC01.

So first things first, lets download hMailServer: https://www.hmailserver.com/download

It does not matter where you will download it. The installation steps are super trivial (next -> next -> finish). By default, hMailServer will be installed in C:\\Program Files(x86\\hMailServer

The next step is important if you want to use a dedicated database for it, however I went for the first option because of simplicity. This will setup a small database onto the DC itself, which hMailServer will constantly use.

Then, you need to setup your password for accessing the hMailServer admin console:

And then you are done! If everything went fine (and I am sure it will) you should see this:

Here, you can edit the default localhost connection or add a new one. I used the DC01 as a hostname since this is the real hostname of my Domain Controller:

After you login to the console, you should configure a domain. My internal AD domain is called lsec.local so I will use the same name here:

After you add your domain, on the left pane, you should see the Accounts tab. From there we can either add a local mail account or use present AD account. I found hMailServer to be extremely easy when it comes to account creation and authorization concepts:

Here, in order to add an AD account, simply right click onto the Accounts tab -> Add AD account:

Then simply specify your Domain and the corresponding user account:

After this step, it is recommended to go to your DNS settings (on the DC) and add an MX record for your mail server:

For the purpose of this demo, I use ThunderBird because of its simplicity, but feel free to improvise. You can download ThunderBird from here: https://www.thunderbird.net/en-US/thunderbird/all/ and it can run on any platform. Again, the installation of ThunderBird is trivial. After installing, you can then try to connect using the local or AD account you created during the previous steps:

If you are unable to connect using your mail client and see something like this:

Then its highly possible that you are auto-blocked from the hMailServer. To resolve it, navigate to hMailServer admin console -> Settings -> Advanced -> IP Ranges. There you will see if there is a lockout and you can simply delete it:

It is also advised to create a new IP Ranges rule to allow emails from specific hosts or subnets:

Now to test the email server and clients, I will use my kali and the sendemail utility. Ideally for future phishing campaigns I will setup GoPhish (https://github.com/gophish/gophish) to handle that, but here we are not yet talking about phishing, but rather the infrastructural perspective.

In order to send emails from sendemail, you can use the following snippet:

sendemail -f <from@domain.com> -t <to@domain.com> -s <DomainServer IP / DNS> -xu <username> -xp <password>

And finally, we can send / receive emails:

Hope this was useful, if so consider a sub or a support

Once again, special thanks to all of my Patreons!