Platform SDK: Exchange Server |
Prevents a file attachment from being opened directly without writing it first to an intermediate file.
See IExchExtAttachedFileEvents : IUnknown.
HRESULT QueryDisallowOpenPatt( LPATTACH lpAtt );
Microsoft Exchange calls the IExchExtAttachedFileEvents::QueryDisallowOpenPatt method when it is about to open the attachment directly without writing it first to an intermediate file. An extension object might elect to disallow opening attachments directly if it has encrypted or modified the attachment and should decrypt or restore it to an intermediate file.
If an error occurs, QueryDisallowOpenPatt should display an error message and return an error. Microsoft Exchange will not continue to try to open the file, nor will it display an error message, but will stop the user action that requested the attachment be opened.