My employer issued a formal policy statement about emails, emphasizing that they are monitoring emails.
There has been considerable publicity about e-mails not being private. People have lost their jobs, even gone to jail when they mistakenly sent a very personal email to everyone in the company. (Such a mistake was part of the jokes in the film "American Pie").
I dislike using email for sensitive personal matters (anything beyond "Want to meet for lunch today?") for that reason. I've gotten burned with personal emails forwarded to others without my consent. I am very careful who has my email address. (I need to establish email on Yahoo as Pat suggested that I could be less cautious with.)
[TELECOM Digest Editor's Note: The only thing -- well, not the only thing, but an important factor where Yahoo Mail is concerned is the extremely high volume of spam/scam mail you will get on your account there within days of starting to use their email. My main complaint with Yahoo Mail is the _huge_ amount of sexually-related spam. PAT]