In addition to sending and receiving zephyrs, owl also can send and receive AIM messages. Before sending an AIM message you must login to AOL Instant Messenger, by using the aimlogin command, with your screenname as an argument:
aimlogin screenname
You will be prompted for your password, which you then enter. Once you are successfully logged in you can send an AIM message by pressing the a key, which will bring up an aimwrite command:
aimwrite screenname
Supply the screen name you wish to write to as an argument and then send the message just as you would send a zephyr, as described above.