You can modify shortcuts by your own choice and preference. To learn how visit section Shortcuts in Settings section.
These are the defaults:
Ctrl + 1 - Mail section
Ctrl + 2 - Calendar section
Ctrl + 3 - Tasks section
Ctrl + 4 - Contacts section
Ctrl + 5 - Notes section
Ctrl + 6 - Attachments section
Ctrl + 7 - Widgets section
Ctrl + Shift + 1 - Sidebar - Contact details
Ctrl + Shift + 2 - Sidebar - Agenda
Ctrl + Shift + 3 - Sidebar - Invitations
Ctrl + Shift + 4 - Sidebar - Chat
F1 - Help
F5 - Send and Receive + Refresh
Ctrl + N - Create new Mail / Event / Task / Contact. Depends on the opened section.
Ctrl + Shitf + N - New all day event / New distribution list. Depends on the opened section.
Ctrl + Shift + M - New mail
Ctrl + Shift + K - New contact
Ctrl + Shift + L - New disctribution list
Ctrl + Shift + E - New event
Ctrl + Shift + T - New task
Ctrl + B - Select Contact dialog
Ctrl + R - Reply
Ctrl + Shift + R - Reply All
Ctrl + F - Forward
Ctrl + Alt + F - Forward as attachment
Ctrl + Alt + R - Resend
Insert - Flag
Ctrl + Q - Mark as Read
Ctrl + U - Mark as Unread
Ctrl + J - Move to Spam/Inbox. Depends on opened folder.
Ctrl + P - Print
Ctrl + Shift + C - Copy to Folder
Ctrl + Shift + V - Move to Folder
Ctrl + Shift + A - Archive
Delete - Delete
Shift + Delete - Delete Permanently
Ctrl + A - Select All
Ctrl + X - Cut
Ctrl + C - Copy
Ctrl + V - Paste
Ctrl + Z - Undo
Ctrl + Y - Redo
Ctrl + Shift + S - Save As
Ctrl + Shift + F - Find
Ctrl + . - Next message
Ctrl + , - Previous message
F1 - Help
F4 - Find in body
Insert - Flag
Ctrl + P - Print
Ctrl + Q - Mark as Read
Ctrl + U - Mark as Unread
Ctrl + Shift + S - Save As
Ctrl + R - Reply
Ctrl + Shift + R - Reply All
Ctrl + F - Forward
Ctrl + Alt + F - Forward as attachment
Ctrl + Alt + R - Resend
Delete - Delete
Ctrl + Shift + A - Archive
Ctrl + Shift + C - Copy to Folder
Ctrl + Shift + V - Move to Folder
Ctrl + J - Move to Spam/Inbox. Depends on opened folder.
Ctrl + . - Next message
Ctrl + , - Previous message
F1 - Help
Ctrl + Enter - Send
F7 - Check Spelling
Ctrl + T - Translate
Ctrl + A - Select All
Ctrl + X - Cut
Ctrl + C - Copy
Ctrl + V - Paste
Ctrl + Shift + V - Paste as text
Ctrl + Shift + I - Insert image
Ctrl + M - Insert image as link
Ctrl + K - Insert link
F4 - Find
Ctrl + H - Replace
Ctrl + S - Save
Ctrl + Shift + S - Save as
Ctrl + Z - Undo
Ctrl + Y - Redo
Ctrl + P - Print