Great for use in to-do lists
How to Cross Out Text in Microsoft Outlook
If you want to keep text visible, but want to strikethrough it, you can use the strikethrough option to format the text. If you are composing an email where you want to use this feature, here is how to use strikethrough in Microsoft Outlook in the desktop and web apps.
Please note: At the time of writing, the strikethrough text formatting option is not available in the Outlook mobile app for Android or iOS.
There are several ways to apply strikethrough to text in Outlook on Windows and Mac.