This information applies to macOS Big Sur (11) through macOS Sierra (10.12).
Open a new email screen or a forward or reply-to screen in the macOS Mail system.
you might’t apply strikethrough in messages while they are sitting in your Inbox.
If you seeMake Plain Textin the menu, then the message is already inrich textmode.
No further action is necessary.
Highlight the text you want to strike through in the body of the email.
Click theSbutton (next toB,I,andUin the formatting bar) to strike through the highlighted text.
That’s all it takes.
