Why do people constantly use office e-mail as a personal e-mail account?
(rhetorical question)

I constantly remind people that office e-mail is subject to the
workplace policies and applicable laws. I remind them that e-mails can
be archived beyond their personal control. I remind them that the
bosses have access to them. I remind them that nothing sent or received
over the e-mail is private to them. Not even if they put private in the
subject line. The e-mail is owned and controlled by the company.

Yet they persist in having personal e-mail sent to that account and get
mad when that information is seen by the employer. They scream bloody
murder over privacy violations even though they have been told time and
time again that office e-mail has not expectation of privacy from the
employer or other employees.

On the flip side of the coin I talk to employers who get beside
themselves over it. Some have gone so far as to read each and every
e-mail (small business) and some will read the e-mails of 'problem

Strict monitoring and control of office e-mail sows the seeds of
discontent and creates a hostile work environment. No control of it
creates a lax and lazy environment. Personally I think employers need
to constantly adjust based on policy and realize that you can't stop
people from misusing the office e-mail accounts.