Ever since I upgraded to OS X Mavericks scrolling within an email message in Outlook 2011 has been choppy. It’s been an annoyance that I noticed immediately after upgrading but only recently started searching the web for a solution.
The solution, and I can confirm that it worked for me, was to change back to pre-Mavericks > Always show scrollbars.
System Preferences > General > select the radio button for Show scroll bars to Always
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