This feature is controllable by user policy. That is, a Domino administrator can set up a user policy so that this feature is "off" (and thus totally hidden) from Samantha.
Throughout the beta, this "recall mail' feature has been ON by default. a Domino administrator has to turn it OFF specifically if he or she does not want the ability to recall mail.
We have made a concerted effort to "turn on my default" all of the new features in Notes 8. Notes has a bit of a history of adding features and then turning them OFF by default, making users or admins take extra steps (for example, did you know that the mail "recipient indicators" --also called the 'to-ness" icons--have been around for several releases, but end users had to go turn them on???)
So, we made a general rule to turn ON all the new features. IS the an appropriate setting for a new feature such as "recall mail"?
ALSO, just in case you DO NOT USE USER POLICIES:
Please let us know ASAP (as in, within 12 hours) because we are at the very end of our development cycle and our window for changin ANYTHING is getting slammed shut... soon!