SpamBayes has no notion of quarantine, nor does it have any
way to indicate that a particular sender sends exclusively ham or spam. Instead,
it looks at the text that makes up the message (including the message headers,
which include the sender), compares it to messages that you've previously
classified as ham and spam, calculates the probability that it's spam, and then
takes action based on that probability.
Assuming you're using the Outlook plug-in, messages that
are classified as spam or possible spam are moved to a folder that you
designate. Training SpamBayes that a given message has been misclassified is as
simple as selecting it and clicking the "Spam" or "Not Spam" button on the
Outlook toolbar. You may have to train on more than one
message.