Exchange 2010 / Outlook 2010 /Outlook 2013 spam filtering

Question

Hi,
We use Exchange 2010 Mailserver and MS Outlook 2010/2013 mail clients. I'm quite confused about configuring junk mail filtering, so can somebody give me few simple answers.
If i'm not wrong basically it goes like that:
Filtering can be made on server/mailbox level, when it can be configured using Exchange powershell. The other way is MS Outlook Junk filtering and it can be configured using GPO.
My first question is, are those two ways completely separated or not? I have found articles which are conflicting in my opinion. For example this speaks how to configure Outlook junk filtering using powershell which should not be possible. Or does Outlook
mean OWA in this example?
http://beccabits.com/2011/10/07/how-to-bulk-modify-safe-senders-list-in-outlook-with-exchange-management-shell/
Second question is if i configure MS Outlook Safe Senders list i can see changes using Exchange powershell which means that mailbox junk filtering can be configured through MS Outlook. Is this correct?
Third question concerns MS Outlook safe senders list which i try to load from txt-file using GPO. Problem is that it works only some users. Checked the situation using process monitor and looks like Outlook reads only junkmailimportlists reqkey and
not the other keys, for example junkmailsafesendersfile. Reqkeys have been loaded from GPO correct anyway. I have tried to fix this and sometimes the only way looks to be updating junkmail settings through OWA and sometimes update-safelist from powershell.
I have tried to update all users safelist using powershell but it doesn't work. How to fix this? We have thousands of users and fixing one by one is not the solution
Thanks in advance
Tried a little more now. Looks like only updating Junk mail list trough OWA helps the situation, when Outlook SafeSenders list do not update using GPO. After using OWA, Outlook GPO works.
Using OWA is not the solution as i said before but is it possible to do the same thing by for example adding some address to every users mailbox safe senders list using powershell? That updates users safelist like OWA do or am i wrong? 
~ Jukka ~ 

Answer 1

Hi Jukka,
Based on my knowledge, Outlook Junk filter is only working on the Outlook client side.
The emails have passed the Edge/Hub server and delivered into MBX server, if the emails matched the Outlook Junk filter conditions, they moved into Junk E-mail Folder directly.
If we don't want the junk e-mails or spams delivered into our Exchange server, we can enable the Anti-Spam and Antivirus in Exchange 2010.
More details in the following articles:
Understanding Anti-Spam and Antivirus Functionality
http://technet.microsoft.com/en-us/library/aa997658(v=exchg.141).aspx
Overview of the Junk Email Filter
http://office.microsoft.com/en-us/outlook-help/overview-of-the-junk-email-filter-HP010355048.aspx
Change the level of protection in the Junk Email Filter
http://office.microsoft.com/en-us/outlook-help/change-the-level-of-protection-in-the-junk-email-filter-HP010356454.aspx
Thanks
Mavis
Mavis Huang
TechNet Community Support