People read the messages in a conference because they are interested in a certain topic, and do not appreciate coming across messages that have nothing to do with the subject of the conference. In some cases, continued off-topic postings may get you banned from a conference, or even from an entire network. Generally, this doesn't have to be a major concern. Just remember that it's probably inappropriate to debate politics in a trading cards conference, or to discuss your favorite basketball player in a technical support conference. If you find yourself getting into a discussion that is off the topic of the conference, try switching to private messages to continue the discussion or move it to a more appropriate conference.
Junk mail exists in the online world as well.
While some junk mail is targeted, and addressed directly to you, other junk mail comes in the form of messages posted in an online conference or newsgroup. Spam messages posted in an Internet newsgroup may be automatically killed by news servers. Chain Letters Use your judgement on this one. Realize that many of your friends may not appreciate chain letters, and many have been around for so long that your friends may have seen them already, but some people think chain letters can be fun and harmless. Sending chain letters to newsgroups or network conferences, however, is generally considered rude.