As you send messages back and forth you will usually respond to mail using the Reply To Feature in Netscape.
(Reply To: will be covered in more detail in just a few pages).  

Basically..., When you choose the Reply To Button (in your Mail Composition Window), the return e-mail address..., and a "copy" of the origional incoming message (optional) is placed in a new Mail Composition Window. Reply To allows you to respond quickly (and accurately) to incoming E-mail.

As you send this message back and forth..., Netscape will "Thread" the messages together. Threading is particularly useful if days have past between messages.

To Thread Messages:
From the Netscape Mail Window Toolbar..., Choose View, then Sort, "click-on" Thread Message"
To Unthread the messages click-on Thread Messages (again).
This will remove the Check to the left of the Threaded Messages

The Minus Shows the Threads, and the Plus Hides the Threads.

Something that happens quite often...,

An incoming e-mail message will appear in your inbox by date, then the next time you look for the message it is gone! This can be caused by Threading a message. Some people have a "bad habit" of grabbing just any message and replying to it (rather than keeping an address book).  If you are "looking for" a message and can't find it... chances are it is threaded to a message and you don't realize it. ...and it is placed with other messages previous to the date in which you are looking!

Threaded Messages allow you to easily follow "important dialog" in your electronic mail!