internal email going to junk folder

Hello,

Our environment is setup with one exchange 2013 server and all clients run outlook 2010.

We are having issues with internal emails from our voicemail server going to users junk folder. I cant seem to find whats causing this. When I check the transport agents get the following:

[PS] C:\>Get-TransportAgent
Identity                                           Enabled         Priority
--------                                           -------         --------
Transport Rule Agent                         True            1
Malware Agent                                  True            2
Text Messaging Routing Agent            True            3
Text Messaging Delivery Agent           True            4
Content Filter Agent                           True            5
Sender Id Agent                                False           6
Sender Filter Agent                            False           7
Recipient Filter Agent                         False           8
Protocol Analysis Agent                      False           9
  I also checked the agentlog to check for possible warnings from that internal email and it shows: .........Content Filter Agent,OnEndOfData,AcceptMessage,,SCL,not available: policy is disabled.,,3343c44a-8ssb-4ds7-44302-08d42e42a98e,,Originating

any help will be much appreciated