Hello,
It looks like that the MX sync is totally broken on the Tru64 UNIX system.
I have only this kind of messages and the MX connections are closed immediately:
milter-greylist: Unexpected reply "102" from a.b.c.d, closing connexion (n entries queued)
I had to move the fflush() call to a better place,
please see the attached patch which fixes the problem to me.
Bests,
Attila