Bob is our in house moderate / comedian / linguist/ astaro guru among other things. So yes pull the plug, it is the safest bet.
You can also just block common extensions like zip, rar, exe, msi, avi etc depending on your needs[;)]
I disconnected the cable and now they have no internet anymore.
Just kidding.
How can I let users go on internet without the rights do download files.
If I block extensions are they then also blocked for mail.
Which is not the intention only for downloading from the internet.
The settings to block file extensions must be made in both Mail Security and Web Security. In each case, go to the Anti-Virus tab.
I don't know if it's possible to have the Astaro block executables in emails instead of just quarantining the emails. We normally do that in the mail server.
Enter application/octet-stream into the MIME type filter under the Web Security/HTTP/S/Anti-Virus section. Or you can block every type of applications by adding in application/* although this will also block PDFs, Word docs, etc. It's best to block only the executable downloads and zips
I also block all audio and video to prevent MP3s and movies (also kills streaming radio and TV) from being downloaded. Add audio/* and video/* to the blocked MIME type filter.
Here is a link to reference MIME types if you want to block a specific file type
Multimedia MIME Reference