0% loss
It comes down to forwarding the DNS of Vimexx to Ziggo's own IP address.
Then you only have 1 cable from the router directly to the server.

The following is the normal existing situation and then everything has internet.
But then you can't have that forged DNS at your disposal

   
If you go from the router with only 1 cable to that server, you can have that DNS at your disposal.
But only when the server is configured and the clients have internet, you can reconnect the rest from that hub.
As long as that doesn't work, the rest has no internet.

Below you see 2 servers because it is not recommended to configure Exchange and the company server on 1 machine
To configure the Mailflow, the Wan needs to be connected directly to
the Exchange server, because the domain is forwarded to the DNS of that server.
Instead of having that server directly behind it, we just need a hub.

Disadvantage is that if the Exchange does not have a network, the rest will not work either.
Upgrading to Ziggo Business Pro provides 5 IP addresses so you can connect multiple servers to it.
This means that you also need to create a number of subdomains and then you need to activate LD-LDS (Lightweight Directory) as a role.
But that has probably already happened because that's why you get a remark with the yellow flag that ADAM is not enumerated and that refers to the fact that you have not yet created subdomains.

Below is a possible solution, but it means that the server has to work.
With restart or if the server is still being configured the rest has no internet.

Netwerk agemeen = Network general

You can also only use the Exchange with Server 2016 (on 1 machine) with a hub/switch.

If you forward Ziggo's IP address to the server, you can use the network as it is now.

But you can also ask what the costs are of having that mailflow taken care of by another company.
To maintain a mail server the company needs a specialist and that costs time and money.
Outsourcing this can even lead to considerable savings.

Because we have another problem.
With the upgrade of the version Windows1903 to 1909 it went completely wrong.
We set the data to D so that on C there is only the OS with the programs.
OneDrive has also been moved to D.
And then it went wrong.
The testers had already warned about it, but those warnings were ignored.

With the upgrade of 1909 OneDrive on C was expected.
However, it was on a different partition. (D)
Because that was not on C it was assumed that nothing was stored there in OneDrive.
And that was synchronized with the cloud and nothing was synchronized with nothing.

Everything gone in the cloud.
Then connect to OneDrive on that other partition and synchronize it with nothing.
It took another 14 days before the rollout was stopped.
And the response of M$:
We will try to retrieve your data, but cannot guarantee it.
Fine, and then you can go to the employer with that info.
Data loss is job loss. That is unforgivable.

Back to the mailboxes of Outlook.
The story above is to understand the following and to be able to estimate the risks.
Until Office 2013 the mail was stored in an Outlook.pst file.
Had you moved the documents to the D then that file was also on the D under Documents/Outlook
So you could put an (older) image back without any risk of losing mail.
Since Office 2016 they use a link with Office 365 and your mail is also stored in the cloud.
Then you no longer have a PST file but an OST file which is set to C and cannot be moved.
You can create a folder on D and then you can create a symbolic link from that OST on C to that folder on D.

That is one direction traffic.

Then you get a copy of C on D but if there is still old mail in that D folder, it will not go to C.
And then the big question.
If you put an image of 6 months old back on C the cloud will put that 6 months mail back in that folder, or is it assumed that you deleted 6 months mail yourself and synchronized it with the cloud, so that mail is lost?

What do you think?
It is plausible that the old mail on D is not synchronized with C and also not with the cloud.

With this information you then have enough arguments to convince the employer that this mail handling (mail flow) is better handled by an external party.
First of all, it costs a lot of time (and money) to install and maintain a mail server.

Time that prevents you from doing other things.
And the employer has to hire a specialist and that also costs more.
Then there is the hacking risk that confidential mail will end up on the street.
It is therefore advisable to request a quote from an external party for the handling of that mail flow.

Storage data on server

Work Folders in Windows Server 2016

Preparations Exchange Mail Server

Create an Exchange folder on D
Put the Exchange ISO ( 6797mb ) in there if it is not there.
Unpack the ISO with 7 zip in the folder
The name of the folder has to be Exchange

It is recommended to have a C (OS), a D (Exchange), and an E (Software).
On that E partition you will find all the already downloaded software you need.

If all of this is already there, you don't have to download anything and you can install it from that E

If after installing a component you get an error message when installing the next component, it is often a matter of rebooting and then trying again.

1
Install Media Foundation Feature
Launch Server Manager (ServerManager.exe), navigate to Manage → Add Roles and Features→ Next → Next → Features → Scroll Down → Select Media Foundation → Next → Install.

2
Install API 4 & API 6 or higher Unified
Communications Managed API 4.5.2. Runtime

Get the updates first, otherwise it won't work.

3
Install Framework 4.7

4
Powershell.
c:\administrator
Install-WindowsFeature Net-Framework-Core -source®network®share®sxs

5
Install Visual Studio 2013 C++

6
Install Update KB3206632

Open Windows PowerShell.  

Here it is assumed that you have the unpacked ISO in the Exchange folder on D!

The ADSI below has not (yet) proved necessary.
You can skip that. Continue here

1. Open Active Directory Service Interfaces (ADSI) Edit. To do this, click Start, click Run, type ADSIEdit.msc, and then click OK.
2. After the ADSI Edit window is loaded, right-click ADSI Edit in the navigation pane, and then click Connect To.
3. In the Connection Settings window, click Select a well known Naming Context in the Connection Point area, and then click Schema.
4. Expand the Schema [DC.domain.com] node, and then click CN=Schema, CN=Configuartion,DC=domain,DC=com.

In the result pane, right-click CN= ms-Exch-Resource-Schema, click Property, and then change the value of the lDAPDisplayName attribute to msExchResourceSchema

 

 

Right mouse button on properties

Go to Display name and edit
CN= ms-Exch-Resource-Schema

Click on the start button at the bottom left and search for PowerShell, then click on Windows PowerShell.

We set the installation directory of Exchange to D under that name.

 

Open PowerShell and navigate to the folder where the installation files of Exchange 2016 are located.
cd d:\exchange

This can take a while per command.

Enter the command below:
Install-WindowsFeature RSAT-ADDS

  
If you see >> press enter  

cd d:\exchange

To install the Features, run the cmdlet below.

 

Install-WindowsFeature NET-Framework-45-Features, RPC-over-HTTP-proxy, RSAT-Clustering, RSAT-Clustering-CmdInterface, RSAT-Clustering-Mgmt, RSAT-Clustering-PowerShell, Web-Mgmt-Console, WAS-Process-Model, Web-Asp-Net45, Web-Basic-Auth, Web-Client-Auth, Web-Digest-Auth, Web-Dir-Browsing, Web-Dyn-Compression, Web-Http-Errors, Web-Http-Logging, Web-Http-Redirect, Web-Http-Tracing, Web-ISAPI-Ext, Web-ISAPI-Filter, Web-Lgcy-Mgmt-Console, Web-Metabase, Web-Mgmt-Console, Web-Mgmt-Service, Web-Net-Ext45, Web-Request-Monitor, Web-Server, ADLDS, Web-Stat-Compression, Web-Static-Content, Web-Windows-Auth, Web-WMI, Windows-Identity-Foundation, RSAT-ADDS
  

D

You can use the Lightweigth Directory wizard if you have Ziggo Business Pro.
Then you get 4 extra IP addresses, with which you can also forward to the DNS of other servers with subdomain names.

cd d:\exchange

To perform the schedule update, run the cmdlet below:
Don't forget the point at the front

.\setup.exe /PrepareSchema /IAcceptExchangeServerLicenseTerms  

Active Directory Schema update is finished.

To make the Active Directory suitable for Exchange 2016 the cmdlet below needs to be executed. When the scheme update hasn't been executed yet it will still be executed in this step. In this step you will need to specify the Organization Name.

The Organization Name cannot be changed afterwards, so choose a name you are satisfied with until the end!

Run the cmdlet below.
You need to replace the command line name company between the brackets below for the organization name.

Copy that line to Notepad and change the company name to the desired one, then paste that line into PowerShell.

.setup.exe /PrepareAD /OrganizationName: "company name" /IA\cceptExchangeServerLicenseTerms

In this case

cd d:\exchange

Don't forget the point at the front

.\setup.exe /PrepareAD /OrganizationName:"kompserver" /IAcceptExchangeServerLicenseTerms

Preparing the Active Directory has succeeded.

Install Framework 3.5
Use Manage, Roles and featurus and click through until you see framework 3.5 at the top.
Install
And that may take a while.

All preparations for the Active Directory have now been completed. To be able to install Exchange 2016 a number of Features will be installed.  

 

Reboot the machine.
  

Installing  Exchange 2016
Mailbox Role in Power Shell

cd d:\exchange

Make sure you copy the first point of the following command line with it 

 

./Setup.exe /Mode:Install /IacceptExchangeServerLicenseTerms /Role:Mailbox /CustomerFeedbackEnabled:False /TargetDir:”D:\\Exchange\\” /DbfilePath: “D:\\ExchangeDb\\” /LogFolderPath:”D:\\logs\\”



It seems that the installation gets stuck at 16%
But the installation takes a total of 30-45 minutes.
Just wait.
 

 

You may get an error message.
The Exchange Server setup operation didn't complete
Then you have to install Exchange from the setup file on D.

Open setup.exe in the installation directory of Exchange 2016. 
So not the exchangeserver file but the setup.exe which is located at the bottom.


It can also take a long time before you get the following in view

Check Connect to the Internet and check for updates, then click Next. After that the updates will be downloaded, if no updates are available this will be indicated. Next the installation files will be copied to a temporary folder.

• Click on Next to start the installation.

Of course we read the 'License Agreement' and of course we agree with it;) Click on Next

• Select Use Recommended Settings and click next

 

 

If you get error messages in Readiness Check after this, restart your setup and choose  do'nt use recommended settings

 

• In the next step, it is important to consider what choice you are going to make. A mailserver suffices with the Mailbox Role. 
  Select only this option and click on Next.

Edge Transport Role

The Edge Transport Role is an optional feature for added security and provides a secure email flow for inbound and outbound email traffic. This becomes important when the mail server is placed behind a DMZ. Unwanted programs and viruses are kept out. Although it's not as strong as other similar products like Exchange Online Protection, it's certainly worth considering if you want to add this functionality to your mailserver. 

 

• If necessary, change the installation location of Exchange 2016. Consider placing Exchange 2016 on a C:\ drive and the Transport Queue and Database on another partition with more storage space and disk performance. For this I would like to refer you to an article from Microsoft: Change the location of the queue database. Click on Next.

 

If you have followed the initial steps of this tutorial, you will not be able to choose an Organization Name now, as we have already prepared this. If you didn't follow these steps you will have to choose an Organization Name in the next dialog box. Then click on Next.

If it has been prepared properly, you will not see the image below.

 

Select No and then Next. If you are using your own anti-virus and/or spam software, this option can be disabled. This can also be changed afterwards

 

• It checks whether the server meets the requirements. That is now the case, click on Install. The installation of Exchange 2016 will start, this may take a while depending on the speed of the server.