Exchange contacts sync fails - 403 Forbidden

I am trying to use eM Client against Exchange 2010 via OWA. Everything works fine (mail, calendar) except contacts sync. I did enable contacts sync logging and it shows 403 - Forbidden error in log. What can be done to remedy this error? Is it client or server issue?
Thanks in advance
Jiří Novák

Hello Jiri,

Could you please send me those logs to

Thank you.
Russel Markosky
eM Client

I have sent the logs to you, please note that sender address will be from domain as that is my workplace address…
Jiri Novak