expression.Offline
expression Required. An expression that returns a Namespace object.
Example
The following Microsoft Visual Basic/Visual Basic for Applications (VBA) example returns True or False depending on whether the Namespace object is currently online.
Sub Off()
'Determines whether Outlook is currently offline.
Dim olapp As Outlook.Application
Dim nmsName As Outlook.NameSpace
Set olapp = New Outlook.Application
Set nmsName = olapp.GetNamespace("MAPI")
MsgBox nmsName.Offline
End Sub