Anyone solved this? We have exactly the same problem and strange thing is, the FQDN doesn' t work.
For example, we have a policy with ID 1 for HTTPS without SSL Inspection. Everything works so far, as well the Lync authentication. When we enable SSL Inspection on this policy, we can' t authenticate anymore, because of the certificate mismatch.
So we created a new policy with all the FQDN address for Office365 as destination with the ID 133 and placed this policy on the TOP and without SSL Inspection of course. But you know what, all traffic is still going through the policy 1 and ignores the new policy 133.
After all the troubles I had with 5.0.4 after updating from 4.x and the bad experience I had with the Fortinet Support with my 2 last cases, where it took 2 weeks just to get any reaction from them, I almost lost my trust in Fortinet right now
The support " engineer" really suggested us to reset the FG and start from scratch. He could see our FG has a strange behaviour, but he can' t reproduce it in their lab. To get this answer took 4 weeks and plenty remote-sessions.
Does anyone know if we forgot any FQDN needed for Lync authentication? We checked all the Microsoft TID' s and couldn' t find any others than what we have already. But I guess it must be something like that