Some of the users on EXMB01 are not able to see users calendar Free / Busy information on EXMB02.

In our exchange 2013 (CU5) environment the following server: mailbox EXMB01 and EXMB02, CAS EXCAS01, EXCAS02 and EXCAS03. Server are Windows server 2012, mail domain is mail.domain.com and does not match our internal network of local.domain.xyz (Non standard was setup before me).  All setting point to mail.domain.com for mail configuration.  External cert from a CA was added to all three CAS servers.

USER1 on EXMB01

USER2 on EXMB02

USER3 on EXMB02

Was able to get USER1 to see a USER3 can see all Free/Busy, subject, location now (only set the Free/Busy time) .  Added USER02 see Free / Busy, subject, location (also only set Free/Busy time). Added my own calendar to the USERS01 to the USERS01 outlook and can see my Free/Busy, subject, location.  I only have by default Free/Busy time set no one else added.

What settings to I check first? Is their a PowerShell command to reset a users calendar permissions?  Is something not set correctly on the servers? 

http://public.wsu.edu/~brians/errors/their.html

Get-MailboxFolderPermission

https://technet.microsoft.com/en-us/library/dd335061

Set-MailboxFolderPermission

https://technet.microsoft.com/en-us/library/ff522363

Found that it was incorrectly configured Certificates for the Exchange Back End.

The certificate bindings for 444 should be configured to use the self-signed certificate.  Once configured the to use the correct cert and recycled all the application pools and restarted IIS.  Now everything is working correctly.

• Marked as answer by Friday77 18 hours 1 minutes ago