For requesting a WebOffice 10.4 SP2 license you first need to determine the primary MAC address of the WebOffice 10.4 SP2 Application server machine.
The fastest (but not safest) way to get the MAC address is to start the WebOffice 10.4 SP2 administration pages by entering the URL in the browser:
http://<servername>:<port>/<WebOffice Application name>/synadmin
(e.g. http://<myserver>:8080/WebOffice/synadmin)
Standard Password is admin
There go to the tab "License".

Reading the MAC address
Note: Please be sure to use the physical MAC-address only!
Note: The MAC-address is not allowed to relate to any local IP address, i.e. the address cannot begin with 169.254!
Alternatively it is possible to open the command line ("Run…") and enter:
1)cmd
2)ipconfig /all

Open command line DOS box

Using command ipconfig /all
In a second step you need to check whether you have an ArcGIS for Server Workgroup or ArcGIS for Server Enterprise installed. You need to provide this information to SynerGIS when requesting the WebOffice 10.4 SP2 license.
With the MAC address of your web application server you are ready to request a license file from SynerGIS.