If I copy some text from one document and paste it into an email in Microsoft Outlook 2016 (Mac), I can see that the formatting is present in the clipboard, as the text briefly appears (for less than a second) formatted as it was in source, and then promptly changes into the same format as the email document I'm pasting into. This 'Paste and Match Formatting' is a handy feature most of the time. Sometimes, however, I want to copy-paste some text into an email, such as some code from MATLAB, and I don't want to match the style of the document I'm pasting into. Any attempts to Google this are met with people helpfully explaining how to ensure that text matches the destination's formatting. However, I am trying to achieve the opposite of this. I can paste it into Word with the formatting retained, but not into Outlook.
Go to your email message, and select Edit > Paste.
At the bottom of the pasted text you'll see a paste control icon. Click it to reveal your paste options:
Keep Source Formatting keeps all of the original formatting and images.
Match Destination Formatting changes the font to match what you're using in your message. Images are unchanged.
Keep Text Only removes all of the formatting and images and leave only the text.
Select the desired choice.