Anyone have any ideas what may be causing this delay?
Hard to tell without full tcpserver command line. Make sure you're not doing slow things like identd lookups (you say you have -R which turns that off, so it's probably something else).
If it's not that, do you have a local caching dns server (I use djb's dnscache)?
You might also want to consider the new SelectServer instead of TcpServer (in CVS) which handles many more concurrent connections (though will probably break at around 1000 and you'll need to up your ulimit) and probably performs slightly better. Though it's slightly premature at the moment - might need either some extra hands or another couple of weeks before it's absolutely solid, but I've been running it happily here now for a few days (processed a few thousand mails through it).
Matt.
