Yes, if you set Do Not Disturb on your mobile, MultiLine Desktop will not ring either and the calls will go to voicemail.
Yes, if you set Business Hours, calls outside business hours will go to your voicemail and MultiLine Desktop will not notify you of the calls.
We don't currently support directly uploading MultiLine local contacts or native contacts to MultiLine Desktop. There is no sync between mobile MultiLine local contacts and MultiLine Desktop.
Currently, we support access to Exchange Contacts. If you add your local or native contacts to the Exchange server, you'll be able to use them in MultiLine Desktop.
No, there is no call blocking currently for Desktop. We are currently working on adding the ability to block numbers in MultiLine Desktop.
You can only use Exchange contacts with your registered email. Once you sync to Exchange, it is impossible to return back to local contacts. We are working on adding the ability to return to local contacts, and to use Native and Local contacts options.