Originally Posted by Daveoc64
Anything you send to your <YOURNAMEHERE>@free.kindle.com or @kindle.com, will be stored by Amazon.
If the file is a .mobi or .azw, Amazon will also synchronize your last page read between compatible devices (currently Kindle Keyboard, Kindle Touch, Kindle (4th generation) and Kindle Fire).
Any books that you have purchased/downloaded for free without DRM should be fine to send to Amazon.
I figure that. My issue would be the privacy of my DRM-removed files. I don't want any emails from Amazon claiming I don't have rights to certain mobi files in my collection, especially if they are books on market with drm removed.