A shared calendar does not automatically show up in Outlook, even if you have accepted the request to share a calendar through the web interface. This also goes for shared contacts and mailboxes.
To manage a shared item in Outlook, please follow the next few steps.
Go to “File” > “Open” > “Other Users Folders”.
Next choose the item you would like to open. You can choose between the Calendar, Contacts, Logfiles, Notes, Inbox or the Tasks.
After having made a choice concerning the item you want to open, you need to enter the person’s full name. This is the name by which the person is known in the system. This will also be the same name that is shown whenever that user sends an e-mail, as the senders’ address.
You can also use a “Global Address List”. In the screen shown above, you can click on “Name” and use the select list to choose the option “Global Address List”. You will then be presented with a list of all possible accounts you can reach.