[imnuts]

Here is the tree I have under HKCU\Software\Microsoft\Inbox\Settings
LastSimStatus
OEM
Shortcuts
-Default
--0
--1
--2
--3
--4
--5
--6
--7
--8
--9

The values contained in settings are:
CommaAsSeparator
DisableSMSDeliveryReceipt
IncludeOriginal
IndentBody
LeadChar
MoveMessage
MsgClassOrder
POP3MaxLinesToDownloadWithHeaders
SaveSent
ShowDateTime
SMSAvailable
SMSCallbackNumber
SMSCallbackNumberReady
SMSDeliveryNotify
SMSUnicode
TrashEmpty
WarnOnDeleteSoftkey
ZoomScales

Let me know if this isn't what you needed or you need more info. I won't be around until basically this time tomorrow night to really respond though as I'm working pretty much all day.