Yes. Spam Filtering is an easy way for you to identify spam and to prevent spam posts to the group.

All messages posted to your group are routed through SpamGuard. If a message is identified as potential spam, it will be put in a special Pending Spam folder where you or another moderator can review and either approve or delete the message.

You have the option to turn this feature off. In this case, members' own email spam filters may redirect messages they identify as spam. And Yahoo! Mail users will continue to be protected by Mail’s SpamGuard system.

Note: If you approve a message that was in Pending Spam, it will no longer be considered spam.