Prevent SPAM bots from harvesting email addresses from my website

Prevent SPAM bots from harvesting email addresses from my website

Mainly the reason for taking this action is because the spambots have been harvesting the email addresses on my website and abused them by sending lots of SPAM crap. I was really annoyed by receiving tons of SPAM emails. I managed to reduce the SPAM emails I receive to a minimum by deeply configuring my email server set-up, implementing SpamAssassin, various RBL filters and using postgrey to filter all this SPAM emails but all this is on the server side and it does not prevent spambot harvesters to fetch the email addresses on a particular website, so...