I found a new stamp from my friend but I can't use it when I'm writing a letter. SLOWLY Team October 02, 2017 12:31 Updated Received stamps will be added to your collection, but you can't use it unless you've unlocked it. Learn more about "My Stamps" and "Stamps Collection". Related articles What are the differences between "My Stamps" & "Stamps Collection"? Comments 0 comments Please sign in to leave a comment.