Sign-up addresses (aka revocable addresses) in Exchange 2010
Some of you may have noticed the Sign-up Address option listed under Organizational Configuration > Hub Transport > Global Settings.
This feature will allow end-users to provide temporary e-mail addresses when signing up on a site etc. that may not be 100% trusted. When a user receives a message at the provided e-mail address, they know the message came from the specific site they gave it to.
- Henrik Walther