--- backend.c
+++ backend.c
@@ -6949,7 +6949,7 @@
 	|| (nCmailMovesRegistered + nCmailResults == nCmailGames)) {
 	sprintf(string, partCommandString,
 		appData.debugMode ? " -v" : "", appData.cmailGameName);
-	commandOutput = popen(string, "rb");
+	commandOutput = popen(string, "r");
 
 	if (commandOutput == NULL) {
 	    DisplayError("Failed to invoke cmail", 0);