I don't know a ton about MS Dynamics. But I think you are going to have to create some duplicate detection rules. Here is an article that I found: http://msdn.microsoft.com/en-us/library/gg309427.aspx
However, it looks like that solution is only good for MS Dynamics CRM 2011 and MS Dynamics CRM Online, so it may not work for you if you are using the newest version.