using Outlook or Outlook Express?
To see if a post is crossposted...
this seems to vary with the version (Microsoft, doncha just love 'em). One
person found they had to click on "New post", "View", "All headers".
Another says that with the Outlook Express that comes with IE4 you have to
click "Compose message", "View", "Full headers". You get the general idea.

To block posts from a person.

If you are using Outlook Express, as with other troublemakers here,
either use the Message Rules (which is similar to Netscape or Mozilla)
to copy/paste the posting name and email address into the rules
or plonk,

Highlight/select the post.
Click on 'message' between 'tools and help' at the top of OE...
then click on block sender..

CaliforniaLyme
CaliforniaLyme@cs.com

ironjustice@aol.com
ironjustice@aol.com

other software
<http://www.hyphenologist.co.uk/killfile/killfilefaqhtm.htm>

Google users cannot easily see the headers, cannot block.
Use
Newserver:
http://news.individual.net/  $ ~25.00 per year for a reliable news server

Newsreaders:
http://www.forteinc.com/main/homepage.php
http://www.mozilla.org/
http://www.microsoft.com/windows/ie/using/howto/oe/gettingnews.mspx
http://xnews.newsguy.com