@dbn. You don’t need to log in to valorapps.com to download Easy File Uploader. It is freely available on the webpage: https://www.valorapps.com/web-products/easy-file-uploader.html.
Also, I don’t know what you are referring regarding the easydiagnostic.php, since that too also has FILEINFO_MIME_TYPE. So, as you said, whoever changed it, changed it everywhere in your copy of the module.
As for the activation email, that would have been sent to you automatically. Please check your spam filter just in case the email got sent to your spam folder. If you need any direct assistance, please email me at support[at]valorapps[dot]com. I don’t want to list your email address on this forum.