[Smartie]

I downloaded a book from Manybooks,it is a epub version and no DRM. I connected my kindle to laptop, I thought I should first covert to Mobi format from Epub and send to kindle. but I mistakenly click send to main device without convert first, then Calibre asked me whether I should convert first before send and I click yes, then I found I can read it in my kindle. Is this correct way to send Epub books to kindle? or just because the book I sent is non DRM version,so it can do it? I googled and everyone said I need covert first by Calibre and copy to kindle folder.

Thanks