Outlook free busy service always returns ’no information’

When adding invitees to an event, Outlook returns 'no information' for the availability of the selected contact.

Depending on the version of Outlook, there are a few different reasons for this behavior.


Kerio Connect returns the free/busy data for the time interval of two months by default. This is due to security reasons as there are clients which do not respect the interval settngs and may cause performance issues on the server by requesting whole calendar all the time free/busy information is required. Default interval can be configured in Kerio Connect configuration file.

<variable name="OutlookFreeBusyInterval">2</variable>

  • The user has never logged in - Before any free/busy information is available, the user must have at least a calendar. A calendar will not be created until a user logs into their account.
  • The option to publish at some location has been enabled in Calendar options- In all Outlook versions, the option to publish free/busy information must be unchecked. By default, this option is already unchecked. This option is located under Tools > Options > Preferences > Calendar Options > Free/Busy Options
  • Outlook is using cached browser information -Outlook Free/Busy uses HTTPHypertext Transfer Protocol - A protocol for exchange of hypertext documents in HTML., and therefore borrows information cached by Internet Explorer. It is required to clear the offline cache. This is located under Tools > Internet Options > General. In the "Temporary Internet Files" section, choose the "Delete files" button.
  • The Microsoft Web Publishing Wizard is not installed (Outlook 2000 only) - In Outlook 2000, it is necessary to download and install the Microsoft Web Publishing Wizard. Although the download link mentions support for Windows 98/NT, it will work on any Windows OS. There is no configuration necessary in the installer.
  • Internet Explorer setting is not correct - An Internet Explorer setting may prevent the .ics file from downloading via HTTPSSecure version of secured by SSL.. In Internet Explorer on the Outlook computer, go to Tools > Internet Options > Advanced. In the Security section, the checkbox for "Do not save encrypted pages to disk" should be unchecked.