Before you believe any email that is sent to you warning about some dire consequence and telling you to warn all your friends please do the following.
You can turn off the daily Quarantine report from the antispam appliance.
Why do I have to receive SPAM at all? Why can't it be deleted at the server before it comes to my inbox?
Using your personal preferences in the antispam appliance you can BLOCK/blacklist email addresses or whole email servers.(DOMAINS)
Here is an easy way to modify your antispam appliance settings so that it won't put your friend's email in the quarantine.