Here is a selection of useful Microsoft Outlook Keyboard Shortcuts:-  

ActionShortcut Key
Advanced findCtrl + Shift + F
Change the number of calendar days that displayAlt + (any number from 1-10)
Check for a new e-mailCtrl + M or F9
Check namesCtrl + K
Check spellingF7
Copy an itemCtrl + Shift + Y
Create a meeting requestCtrl + Shift + Q
Create a message (from any Outlook view)Ctrl + Shift + M
Create a message (when in Mail)Ctrl + N
Create a new appointmentCtrl + Shift + A
Create a new contactCtrl + Shift + C
Create a new contact groupCtrl + Shift + L
Create a new email messageCtrl + Shift + M
Create a new faxCtrl + Shift + X
Create a new folderCtrl + Shift + E
Create a new journal entryCtrl + Shift + J
Create a new Microsoft Office documentCtrl + Shift + H
Create a new noteCtrl + Shift + N
Create a new taskCtrl + Shift + K
Create a search folderCtrl + Shift + P
Create a task requestCtrl + Shift + U
Delete an itemCtrl + D
Dial a contact phone numberCtrl + Shift + D
Display Send/Receive progress (when a Send/Receive is in progress)Ctrl + B
Display the current month in calendar viewAlt + =
Display the current week in calendar viewAlt + –
Expand search to include items from the current folderCtrl + Alt + K
Expand search to include subfoldersCtrl + Alt + Z
Find a contactF11
Find a message or other item (Go to Search box)Ctrl + E
Flag a message for follow-upCtrl + Shift + G
Forward a messageCtrl + F
Forward as attachmentCtrl + Alt + F
Go back to the previous view in main Outlook windowAlt + Left arrow
Go forward to next view in main Outlook windowAlt + Right arrow
Go to different folderCtrl + Y
Go to the next messageDown arrow
Go to the previous messageUp arrow
Mark a message as not junkCtrl + Alt + J
Mark a message as readCtrl + Q
Mark as unreadCtrl + U
Move an itemCtrl + Shift + V
Move around message header lines in the Folder Pane or an open message.Ctrl + Tab
Move around within the Folder PaneArrow keys
Move between the Folder Pane, the main Outlook window, the Reading Pane, and the To-Do Bar.Ctrl + Shift + Tab or Shift + Tab
Move between the Outlook window, the smaller panes in the Folder Pane, the Reading Pane, and the sections in the To-Do Bar, and show the access keys in the Outlook ribbon.F6
Move between the Outlook window, the smaller panes in the Folder Pane, the Reading Pane, and the sections in the To-Do Bar.Tab
Open a received messageCtrl + O
Open address bookCtrl + Shift + B
Open the MailTip in the selected messageCtrl + Shift + W
Post a reply in this folderCtrl + T
Post to this folderCtrl + Shift + S
Print an itemCtrl + P
Reading Pane, go to the previous messageAlt +Up arrow or Ctrl + comma or Alt + Page Up
Reading Pane, page down through textSpacebar
Reading Pane, page up through textShift + Spacebar
Reply all to a messageCtrl + Shift + R
Reply to a messageCtrl + R
Save (except in tasks)Ctrl + S or Shift + F12
Save and close (except in mail)Alt + S
Save As (only in mail)F12
Search for text within an open itemF4
Send a messageCtrl + Enter
Send and ReceiveF9
Send or post or reply allAlt + S
Switch to CalendarCtrl + 2
Switch to ContactsCtrl + 3
Switch to Folder List in the Folder paneCtrl + 6
Switch to InboxCtrl + Shift + I
Switch to MailCtrl + 1
Switch to next message (with message open)Ctrl + period
Switch to NotesCtrl + 5
Switch to previous message (with message open)Ctrl + comma
Switch to ShortcutsCtrl + 7
Switch to TasksCtrl + 4

Post a comment if we have missed any that you regularly use!