How do you mail to ALL your recipients (addresses) at one time in O.E.

   I am not sure what you mean by "all your recipients".  Are you talking about a Reply All option?  That is available in OE.  If it is not on the toolbar, look in the Message menu.

I mean I want to  send the same e-mail to all the addresses in my address book.

    There are many ways to do that but the best way is to click on the To: button.  This will open the Select Recipients dialog.  Select all of the recipients in the list that you want to receive your email.  To select all of them, select the first one, then scroll down to the last one, hold down on the Shift button, and select the last one.  Once you have the recipients selected, click on one of the three buttons to the right: To:, Cc:, Bcc:.  The email addresses will be put in the appropriate box.
    Bcc (which stands for Blind Carbon Copy) is the best one to select when sending to a list of people because it hides the email addresses from everyone.  Most people do not like having their email address sent to everyone on your list (which is what To and Cc will do).
    Then click on the OK button.