Uploaded file not sending through mail (only showing the file name)

I have read this : https://contactform7.com/file-uploading-and-attachment/ and followed each option to send mail with attachment but i do not get the attached file. Others working fine.
Here is my form : contactform
If i put the [your-file] message body, i can get the file name in mail. So how can i confirm the plug-in uploading attachment correctly ?
And why the attached file doesn’t attach with mail ?
the upload folder “wpcf7_uploads” has the permission 777
PHP version used for this site is : 5.3.8

Thanks,

https://www.ads-software.com/plugins/contact-form-7/