Internet Direct (Indy) Version 9.0.2 Beta
TIdAttachment.FileIsTempFile
Indicates the storage for the message part is a temporary file.

property FileIsTempFile: boolean;
Description
FileIsTempFile is a Boolean property that indicates that storage file indicated in FileName is a temporary file. FileIsTempFile is used in Destroy to determine if the storage file should be deleted when the object instance is freed.