if you don't see the "Recall Message..." button in your Sent items, then your IT help desk or Domino administrator did not enable it for you.  Call your IT help desk and if they restrict this feature in your company for some reason, then you can try an IBM Notes message recall tool such as "TOTAL Recall".  However, your company will need to purchase this tool since only your IT department can install it for you.  It can be configured to allow you to recall a message, or allow your  IT help desk to recall a message for anyone in your company -- central control and risk aversion.

http://www.notesmail.com/TotalRecall

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