|Outlook Developer Reference|
Version Added: Outlook 2007
expression A variable that represents a MailItem object.
|Attachment||Required||Attachment||The Attachment to be previewed.|
|Cancel||Required||Boolean||Set to True to cancel the operation; otherwise, set to False to allow the Attachment to be previewed.|
This event occurs before an attachment is previewed, either from the attachment strip in the Reading Pane of the active explorer or from the active inspector.