KB01120904 Why do some email attachments get renamed to .TxT ?
Mailtraq includes an Executable Attachment Policy which is a safety feature to prevent virus attacks. This is enabled by default so you may need to reconfigure the feature in the Mailtraq Console. Go to Options | Incoming Mail | Options | Settings to make changes.
Mailtraq can "sanitise" an attachment by renaming it to .TxT and although this doesn't render the virus completely harmless, you will need to rename the attachment manually before being able to execute it. The complexity of renaming the file should be enough even to prevent unaware users from running the executable.
If you do not wish to sanitise the attachments, you can disable this and simply add a note to the subject line warning users.