Hi, I think I have the reverse problem. I cannot get calibre to send pdf's to kindle via the kindle e-mail.
Further, I could previously extract the text from pdf's with "text under image" by first converting them to epub and then to mobi in calibre. In the later versions, however, it seems the epub format, too, converts pdf's to image htmls.
All this may have resulted from my insufficient knowledge on the capabilities of calibre... I know enough however to thank you very much for this great program!