In short ... yes!
In fact, if your story is short and suitable for teenage audiences, you may post the entire story on the Yahoo! group.
As you can probably expect, your "SSP" (which is a fandom term meaning "shameless self-promotion") should at least include a link to where the story can be found and should also include a rating and any relevant warnings. You may also find your SSPs most effective when they include a brief summary or at least a list of the major characters.
Last updated 30 May 2008.