title_body: How to sync my Kindle with my Kindle library without using WiFi? This is a question that plagued me a while ago when my wireless router refused to work correctly with my Kindle Touch (3G edition).
  
  I had a document that I wanted to transfer to my Kindle as well as my Kindle Library. Both of these tasks where easy enough to accomplish on their own:
  
  
  I connected my Kindle to my PC via USB and copied it to the appropriate directory on the device.
  I sent an email to my send-to-Kindle email address with the document as an attachment.
  
  
  Unfortunately, when my Kindle would sync via 3G, I would end up with an extra "book" in my library - the document I sent to my library via email. Of course, the document wouldn't download since I wasn't connected via WiFi so I was left with a copy of the document on the device and another copy waiting to download.
  
  Why couldn't my Kindle recognize that I already had the document on the device? Is there any way to add a document / book to your Kindle library and still have the Kindle recognize that it exists when manually copied to the device?
upvoted_answer: Using Calibre you could try :
  
  
  Adding the book in the Calibre library
  Sending the book to your Amazon email address (Right click on the book > Connect / Share)
  Sending the book to your Kindle while it is connected to your computer (Right click on the book > Send to device)
  
  
  Of course this requires some initial configuration (telling Calibre how to send email, ...) and I can not guarantee it will work having no 3G Kindle to test it myself.
  
  But it seems to be worth a try as it would most likely make sure that the file that gets copied on your kindle has the right format/information to be identified correctly.