DL will sell it, however there's 2 issues. 1)AF codeshares on the route, not all days are AF operated. DL won't sell the codeshare IME. 2)MLE/SEZ have a bug in DL system that prevent searching correctly. There will be applicable fares and valid flights, but DL system simply won't return them. It'll require calling in and getting knowledgeable agent (or using ITA MATRIX) to book.