Skype for business federation difficulty, federation works to limited partners

Maybe just a simple question but for me, it's quite a brain breaker at this moment.

Situation:

We have a working Lync 2013 server environment, including an (I think) properly set up Edge server. Since a few months, I configured the federation part, so we can start to connect with some clients. after some setup difficulties, everything went fine, and it worked like a charm.

After set up some successful federations with some clients, I start to get some problems with some partners.

The companies (that give us some troubles) have all a hosted Office 365 solution (directly from Microsft). They have various working Federations, with hosted solution - 365 - and on premises -Lync 2013 / 2016 - solutions. So we are differently the company that has a configuration mistake.

After some investigation from my side, I found out that all federations I have working on my side are setup to clients with an "on premises" / "dedicated" solution.

So the problem basically is: "we cannot connect to Skype for Bussiness environment that are hosted by Microsft / Office 365" (they use this FQDN: sipfed.online.lync.com)

I followed this link: https://technet.microsoft.com/en-us/library/jj205126.aspx (especially this part: Configure your on-premises Edge service for federation with Skype for Business Online)

and our setup passed all connectivity tests successfully:

https://testconnectivity.microsoft.com/ and

https: //www.eventzero.com/ Tools/FederationTester3/

I see the contact status from the clients as "Presence unknown" and if I send a message I get the follow waing: "This message wasn't sent to [email protected] due to company policy"

but which "company policy" is for me a black box....

Hopefully, someone can help me because I'm pretty out of idea's

Thanks

Recent Questions...