Configuration: Define Access URLs for Exchange 2016
Contents
For the moment, the Exchange 2016 server is configured to send the fqdn.lab.intra url to the client. With this configuration, it is not possible to access Exchange with Outlook from outside.
It is necessary first to define the address that will be used to access the server from outside.
To illustrate the tutorial, I will use the address mail.rdr-it.com
Editing directories by ECP
Outlook AnyWere
Outlook Anywhere allows your users to connect to their Exchange mailboxes through Outlook.
1. From the ECP interface, go to servers 1 , select the server in the list 2 and click on the edition icon 3 .

2. Go to the Outlook AnyWhere 1 section and enter the external address 2 then Save 3 .

3. Close the warning by clicking OK 1 .

Virtual Directories
1. From the ECP interface, go to servers 1 then virtual directories 2 .

2. Select the ECP directory 1 and click on the edit icon 2 .

3. Configure External Url 1 then click Save 2 .

Make a copy / paste of the internal URL in the external and replace the name fqdn of the server by the external url by keeping the parameters of the url.
4. Close the warning message by clicking OK 1 .

5. Repeat for all directories except the Autodiscover.
Editing Directories by Scripts
There is a script, which allows to make the changes by a powershell script.
1. Download the script on the Exchange 2016 server.
2. Open the Exchange Management Shell and go to the folder where the script is located.
3. Run the script:
.\ConfigureExchangeURLs.ps1 -Server LAB-EX1 -InternalURL lab-ex1.lab.intra -ExternalURL mail.rdr-it.com