These files have .bad extensions. Please look for .bad files, and make sure that the content is valid.

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Computer:  Server
Source:       MSExchangeTransport
Category:  Pickup
Type:         Error
Event ID:  9010
Description: At lease one file in C:\Program Files\Microsoft\Exchange Server\TransportRoles\Pickup cannot be processed. These files have .bad extensions. Please look for .bad files, and make sure that the content is valid.
Explanation
This Error event indicates that one or more message files that have been classified as badmail exist in the Pickup directory or in the Replay directory. A message that is classified as badmail has serious formatting errors that prevent the Pickup directory or the Replay directory from submitting the message for delivery. Message files that are determined to be badmail are left in the Pickup directory or the Replay directory and are renamed from filename.eml to filename.bad.
 
User Action
To resolve this error, do one of the following:

If you want to discard the message files that have been classified as badmail, you can simply delete the message files from the specified location.

If you want to fix and resubmit the message files that were classified as badmail, follow these steps:

Move the message files that have been classified as badmail from the specified directory to a different location.

Change the file name extensions from .bad to .eml.

Resolve the errors in the message files.

Copy the message files back into the specified directory for delivery

More Info at: 

Understanding the Pickup and Replay Directories

Event ID 9010