- snprintf (message_id_, sizeof message_id_, format,
- getpid (), (long) now.tv_sec, (long) now.tv_usec,
- one_third, rnd_base64,
- one_third, &rnd_base64[one_third],
- one_third, &rnd_base64[2*one_third]);
+#define P(fmt) \
+ snprintf(message_id_, sizeof message_id_, (fmt), \
+ getpid(), (long)now.tv_sec, (long)now.tv_usec, \
+ (int)one_third, rnd_base64, \
+ (int)one_third, &rnd_base64[one_third], \
+ (int)one_third, &rnd_base64[2*one_third])
+
+ if (content_id)
+ P("<%d-%ld.%06ld%%d@%.*s.%.*s.%.*s>");
+ else
+ P("<%d-%ld.%06ld@%.*s.%.*s.%.*s>");
+#undef P