Outlook - Change text between upper, lower and mixed case

Sometimes when writing an e-mail in Outlook I would like to change the case of my text. For example, recently I was listing usernames and they were all lower case. Sometimes there were typos (often due to Outlook's auto-correct) so if I could select those words and force them to lower case, that would be great.

Menu
In Outlook 2013 click the Format Text menu and the Aa button:

Keyboard
Even more useful than that, you can use the shortcut Shift-F3:

Shift-F3 works in Outlook, Word and Powerpoint. I have tested with Office 2013, it is likely to work in other versions of Office, older and newer. Try and write in the comments what you discover.

Shift-F3 doesn't work in Excel. Shift-F3 in Excel is to insert a function.