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CallTower Solutions Center

Skype for Business contact(s) presence unknown or exchange issues

Skype for Business is able to integrate with Exchange to provide a robust user experience. When Skype for Business and Exchange are unable to communicate, usability is reduced. 

Contact(s) seem to be offline in Skype for Business

Ensure that the contact is not blocked. 

  1. In the main Skype for Business window, select Relationships
  2. Expand the Blocked Contacts group, and then verify that the offline contact isn't blocked

Note: If a contact blocks you, that contact will be displayed as offline in your contact list

After you add a new public IM Connectivity (PIC) contact or a new federated contact to your list, that contact will appear to be offline until the contact accepts the request. Verify That;

  • Federation is enabled
  • Federation with Skype is enabled for contacts outside of Skype for Business

You can't search the global address list by using Skype for Business

Skype for Business address book and GAL lookups are performed through web requests only. Skype for Business doesn't download or save a local copy of the address book. This reduces the load on the servers and provides the most up-to-date information possible when you perform a contact search. When you try to search the address book Skype for Business, you receive one of the following error messages:

“Cannot synchronize with the corporate address book. This may be because the proxy server setting in your web browser does not allow access to the address book. If the problem persists, contact your system administrator.”

“The address book is preparing to synchronize. Search results might not be current.”

Verify connectivity to Exchange Web service is available. To do this, follow these steps:

  1. In the notification area on the right side of the taskbar, Hold down the Ctrl key and right-click the Skype for business icon


  1. Select Configuration Information, a new window will open.


  1. Verify that the EWS Status OK is present
  2. Verify that MAPI Status OK is present

If Present: no action needed

If EWS not deployed or missing: Work with the Exchange administrator to ensure Autodiscover and EWS are set up correctly. 

  1. Open a web browser and navigate to the EWS External URL. If the URL ends in WSSecurity, omit that from the address.

If Successful: You will be prompted for credentials

If Unsuccessful: Work with the Exchange administrator to ensure Autodiscover and EWS are set up correctly.