I'm running emailservers for years now and never ran an identd. And my clients don't have an identd running either. I don't think that you need this for smtp nowadays.
identd is a protocol intended back in the day when the internet was
a connection between Bolt, Beranek, & Neuman, MIT, and Stanford
University, (and maybe a few other labs) and called the Arpanet,
to announce to a client machine connected on that port; "Who's there?",
and then the client responds with its lab (or campus) banner. That's
it. Its pointless now, not needed, infact; a security risk. You don't
need it, nothing now depends on it, and if your distro or flavor
of Unix allows it, its best disabled (with inetd). Deffinately
block it off with pf.
