This listing does not show up in the MLS, although it is showing the "agent" as Fannie Mae who is currently shown as the owner of record. I would use the Contact Agent button on that listing to find out. It might be wise to create an email address to use that you can delete if this person does not seem to be legitimate. I would also not give any person information to them until you verify that they are the legal/legitimate representative for Fannie Mae. The previous listing was withdrawn Jan 2008 so this is a new listing, just not listed in the MLS system. It is possible that it is listed by a real estate agent that is not a Realtor - a Realtor is a real estate agent that is a member of the National Association of Realtors, you do not need to be a member to be an agent.