School employee loses job because he sent an email containing a one word obscenity to a blog.  See ABA article.  When the employee was confronted with the email, he resigned.  Another example of someone who publishes something controversial on the internet under the mistaken belief no one will ever see it. 

Personal emails at work are sometimes protected from intrusion and sometimes not.  The email system belongs to the employer.  One indicator that work generated emails may be protected occurs when the employer allows some personal use of email.  See the case discussed at one blog post.  But, see another case discussed at a different