[exim] Speed of SMTP Banner

For some reason the SMTP banner takes several seconds (between 4 and 8) to
respond. It looks odd as if I telnet to the POP port (110) I get an
immediate response, while port 25 is slow.

The machine has dual processors and is idle, so I would epxect a faster
response. DNS queries on the machine are immediate, and my config file is
basically the dafault.

Also on the machine telnet 0 25 is immediate? so why not remotely.

Exim is not wrapped or anything like that and was started as exim -bd -q1h

Any clues?
Gary