Systems and methods for allowing challenge messages to be sent directly to
a recipient's inbox where normally the challenge message would be sent to
a pending folder or deleted. Challenge messages sent between federated
messaging services contain a federated token which can be identified,
authenticated and validated to determine whether the challenge message
should be sent to a recipient's inbox. The federated token can include an
authentication portion and a validation portion. Authentication methods
for the authentication portion can include, for example, checksums,
salts, hashes and digital signatures. Once a federated token is
authenticated by decrypting the authentication portion according to one
or more of these authentication methods, the federated token is validated
by determining the defined use-base and determining whether the receipt
of the federated token satisfies the defined use.