When you right click on Outlook in the task bar, you can select one of the shortcuts from the Jump list. However, it's not uncommon to lose the jump list if you uninstall or repair the Office installation.
To fix it, you need to delete a registry key and restart Outlook. If you have Outlook pinned to the start screen and/or taskbar, you need to unpin it before restarting Outlook, then re-pin it.
Outlook 2016
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook
Delete this value: LastUILanguage
Outlook 2013
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.0\Outlook
Delete this value: LastUILanguage
Outlook 2010
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\14.0\Outlook
Delete this value: LastUILanguage
If you don't want to edit the registry yourself, download and run the appropriate registry file for your version of Office:
Outlook 2016 Outlook 2013 Outlook 2010
Tip: you can pin templates and drafts to the jump list for easy access.
Alternate fix: Change First-Run registry value to True then restart Outlook.
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Setup
String: First-Run
Value: True
Ready to use Reg key. First-Run-2016.reg
To use, double click to run. If your browser opens it as a text file, you'll need to right click on the link and download the file then change the file extension to reg.
More Information
Tip 974: Using shortcuts to create new Outlook items
Tip 986: Link to a Draft Message
Published October 10, 2015. Last updated on May 25, 2016.