If mail to a person doesn't make it through, avoid posting the message
to a newsgroup. Even if the likelihood of that person reading the
group is very high, all of the other people reading the articles don't
give a whit what you have to say to Jim Morrison. Simply wait for the
person to post again and double-check the address, or get in touch
with your system administrator and see if it's a problem with local
email delivery. It may also turn out that their site is down or is
having problems, in which case it's just necessary to wait until
things return to normal before contacting Jim.