.Bad files are emails that could not be delivered by the Microsoft Exchange Server. There is a number of reasons for this, for example, an incorrectly formatted email.
These files can be found in the Exchange pickup or replay folder. The table below lists the default location for each version of Microsoft Exchange:
|MS Exchange Version||Default Location|
|Exchange Server 2003||C:\Program Files\Exchsrvr\Mailroot\|
|Exchange Server 2007||C:\Program Files\Microsoft\Exchange Server\TransportRoles|
|Exchange Server 2010||C:\Program Files\Microsoft\Exchange Server\V14\TransportRoles|
|Exchange Server 2013 and 2016||C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles|
- An event log entry is logged in the Application event log when a .bad file is created, however, it does not specifically state the filename that triggered the message. The source is MSExchangeTransport and an Event ID is 9010.
- Exchange does not clear these files automatically, they must be manually removed. They can be reprocessed by renaming the files to a .eml as usual, however, if the formatting is still incorrect they will be renamed to .bad files again.