Antispamming has been around for a long time.  It's a way to keep email address harvesters from retrieving your email address from a newsgroup post and adding it to a list with 1000s of others to distribute or sell for that nasty thing we've come to know as unsolicited junk email. 

It also keeps your email addy a little more private than just displaying it for the world to see.  For instance, there are several 'archiving' services on the Net that scour the newsgroups and archive every post.  Prime examples of this are http://www.deja.com, http://www.nailnews.com or the now defunct http://www.remarq.com.

Without going into the details of "how" harvesters retrieve this information, suffice it to say... if you want to keep your email addy private, antispamming is one option. 

This will launch a new window and the General tab is selected.  Here you will see your "nick" or "sig line" and your email address.  In the email address line, change your email so that it's antispammed by putting some extra verbiage within your email addy.

 For example, my antispammed address might be:  abby@nospam.perfxion.com

Pretty obvious that "nospam" does not belong and anyone replying to me directly should remove this portion of the email addy and as listed, it's not a valid email account.

 Some get more creative, like:  udonotcme@i-am-not-here.com

 But caution should be exercised when electing this type of antispammed addy.  There are domain names of every flavor, and there just might be a iamnothere.com where the email would be received.  If that's tracked back to you, it could just cause a little raucus. 

You might also consider the most courteous NETiquette when antispamming your email address, where you include your actual email address within the body of your post.  This way, it's obvious to other posters that you are antispammed, but there is a means of reaching your email Inbox should they decide to do so.  To the best of my knowledge, where harvesters scan the headers of posts to retrieve email addresses, they do not scan message bodies.

One last note, using an antispammed email address will preclude you from successfully having posts removed that are archived on the services archival services mentioned here.  In order to remove a post from an archival service, a "real" email address is required for verification of identification.