Assume no User-Agent is Kindle

server.go

@@ -233,7 +233,9 @@ func handleFeed(outputDir string, feeds []FeedConfig, s *securecookie.SecureCook
 		var converter convert.Converter
 		if strings.Contains(r.UserAgent(), "Kobo") && kepubConverter.Available() {
 			converter = kepubConverter
-		} else if strings.Contains(r.UserAgent(), "Kindle") && mobiConverter.Available() {
+		} else if (strings.Contains(r.UserAgent(), "Kindle") || (len(r.UserAgent()) == 0)) && mobiConverter.Available() {
+			// Note: Only Kindle browser is that stupid that it forgets to send its User-Agent
+			//	header after user confirms the file is really to be downloaded.
 			converter = mobiConverter
 		}