Security breach of email to send scam

Someone used an email account for out site ribault67.com.  They sent to all the emails in our class. They used and email

( info@ribault67.com ). I am the Webmaster of this site . I have pictures of the email sent out for an appeal of paypal donations for

for a sick child.  This is an unauthorized use of our information.  I don't understand where they got the email of  (info@ribault67.com)

It appears to be someone from that school not in our class but an alumni.  Using the information to solicit. I need to send the email to your security. Please advise so I can forward it. 

Debbie McBride  ( mcbridedebbie20@yahoo.com )

Alice is also still a part of the site but not Webmaster.