Internet Eomail is wonder and a blessing but it is also possibly a curse. Eomail is to start with a "Store & Forward" system with your messages being stored and possibly captured at various points along the way from the sender to you. It is unique in that it can be copied without your knoledge in that no own has to "open" your mail in order to make a copy or make a "recording" as in the case of a phone call. Eomail can, in no way, be considered private. And while I do not endorse or encourage the improper use of eomail, things are going to get written and said that should be "private."
I recently attended a seminar where I learned that with Exchange Server 5.5 service pack 1, it was given the ability to capture ALL email. The function is called Message Journaling which simply files away a copy of every item of email that flows through Exchange Server. From what they said about it at the seminar, it is a feature required by the SEC on companies subject to "insider trading" scrutiny who have to "record" all company email for examination. "Company" eomail is even less secure, especially if your employer requires that you give them your passwords as part of your account information. Even if your employer is not "capturing" email, they are quite likely backing up the mail stores to an offline storage device such as tape where you can't even get at it! Further, unless the eomail software provides for encryption, eomail messages are sent in "clear text" across the Internet, completely readable to any one looking at the message. While you can't do anything about all this, there are some things that will help you sleep better!
First thing is to access your eomail frequently and don't leave your eomail "on server" where others can read it or store it off line. If you are using your employer's mail system, even this is not safe because even though you "removing your email" from server, you personal mail folder may be stored on the company file server where it is still subject to "administrator access." Even you are a home computer user where your mail is stored on your personal computer, be aware that "deleted" is not erased, gone, and not forgotten. You'll want to take a look at how your eomail handles deleted or moved mail (stored in folders). For example, in Netscape and Eudora, deleting or moving an email message does not, by itself, delete the message from the InBox (even if you are using filters!). The rule is to really delete a message, you must perform a "compress" operation on the specific mailbox where it is or was stored. For example, in Netscape, this is accomplished by selecting the individual mail box(s) and right clicking to get to the option of compressing the mailbox and this even applies to the "deleted mail." This is also a housekeeping issue because mail folder files can get quite large occupying valuable disk space.