Help!! I am getting errors on many client systems - all domains using Active Sync where - where outlook 2013 and outlook 2016 with pop an error that you can not get rid of that says:

 

The server configuration prevents you from synchronizing. Contact your system administrator.

File: outlook\pstprx\storeas\utils\airsyncstatuscodes.h
Line: 226
HTTP/1.1 403 Forbidden
FolderStatus: 403
To re-try press F9...
    Error Code:    0x80004005

 

 

This is happening with pretty much all clients using active sync and the newest version of smartermail 15 with the newest update as of may 27th, 2016. Any ideas?? Since it is happening on outlook 2013 and 2016, some domains and some not. the only common thing I can find is they are all activesync. It has to be my server, just can not find what is wrong. I have updated office to include all updates, windows 10 pro machines. Help!!