If all these inboxes are configured in Outlook you can use the Stores collection to iterate over stores and using the Store.GetDefaultFolder method which returns a Folder
object that represents the default folder in the store and that is of the type specified by the FolderType
argument.
If you need to access shared mailboxes you need to use the NameSpace.GetSharedDefaultFolder method which returns a Folder
object that represents the specified default folder for the specified user.
Sub ResolveName()
Dim myNamespace As Outlook.NameSpace
Dim myRecipient As Outlook.Recipient
Dim CalendarFolder As Outlook.Folder
Set myNamespace = Application.GetNamespace("MAPI")
Set myRecipient = myNamespace.CreateRecipient("Dan Wilson")
myRecipient.Resolve
If myRecipient.Resolved Then
Call ShowCalendar(myNamespace, myRecipient)
End If
End Sub
Sub ShowCalendar(myNamespace, myRecipient)
Dim CalendarFolder As Outlook.Folder
Set CalendarFolder = myNamespace.GetSharedDefaultFolder(myRecipient, olFolderCalendar)
CalendarFolder.Display
End Sub