.BDR File Extension
File Type 1Exchange Non-Delivery Report Body File
What is a BDR file?
Body of an e-mail non-delivery report (NDR); contains information about why an e-mail message was not delivered; includes the error code, message sender, and message recipients.
File Type 2Publisher Borders File
.BDR File Association 2
Contains pre-designed borders that can be applied to a Publisher document; includes multiple patterns that can be selected by the user using Publisher's BorderArt feature.
Publisher includes more than 160 borders, which are stored in 15 BDR files. They are stored in the Office\Borders folder.