If you open the folder you will see readme.txt
Follow the install instructions stated there
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INSTALLATION
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1. Download the package and unzip to a temp directory.
2. Copy the entire "admin" folder to the root of your shop. The files are
already arranged and there are *no* overwrites!
3. You'll find "E-mail Archive Manager" under "Tools" in the Admin.
4. By default, email archiving is turned off; to start archiving emails
you must turn it on under
admin->configuration->email options->Email Archiving Active?

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