How to Turn Off Link Preview in macOS Mail
While there are several approaches to work around this new feature in macOS Ventura, as of now there’s no way to globally disable it when using rich text emails. Composing your emails in plain text does. It makes sense when you think about it: plain text is just text and has no provisions for any media functions.
You can do this under
Settings > Composing > Message format > Plain Text.
Make sure that in the “Responding” section, “Use the same message format as the
original message” is unchecked as well.
Afterwards, all email content is just text. As a bonus, you don’t have to worry about the formatting of pasted text anymore.