-smtp_printf("334 %s\r\n", auth_b64encode(challenge, challen));
-while ((c = receive_getc()) != '\n' && c != EOF)
+smtp_printf("334 %s\r\n", FALSE, b64encode(challenge, challen));
+while ((c = receive_getc(GETC_BUFFER_UNLIMITED)) != '\n' && c != EOF)