I discovered that sendmail was taking a long (as in minutes) time to send
the startup banner. The SYN, SYN/ACK, ACK handshake went OK but then a
long delay before the banner appeared.
It seems that rbl.osirusoft.com is off the air and that is causing
problems so I have taken it out of sendmail.c
For some inexplicable reason my sendmail server has suddenly taken to
taking an inordinately long time (like, minutes) before it returns the
sendmail banner to start a session.
The initial SYN, SYN/ACK, ACK handshake occurs OK, but then there is a
lnnng delay before I get the welcome banner
