If the machine likes your password and login information you will get a big welcome message. It will then ask you what type of terminal you are using. Most people have a vt100 terminal type. At this point you will get the prompt for the machine that indicates that it is ready to do what you tell it to do.
"koni@koko.csustan.edu 1% pine"
Here is an example of what the screen will look like when you log in:

To send the message, hit the 'control' button and 'x' at the same time.

Highlight the message and the next screen will have your message.
There are other commands, and I will let you experiment with them as you need them. Here are some things that I have discovered:
1. The mouse does not work
2. The delete key does work in 'pine', you will have to use 'control' 'h' (simultaneously) to delete if you are not in 'pine'.
3. The arrow keys work, use them to move the highlighted line around, when you get the item you want highlighted, hit 'enter'.