Print emails in Mail on Mac
You can print email messages.
In the Mail app on your Mac, select one or more messages or email conversations.
Choose File > Print.
If you selected multiple messages, each one is printed separately.
If text and graphics print smaller than expected, increase the message font size in the Fonts & Colors pane of Mail settings, then print again.
As an alternative to printing messages, you can save them as files or PDFs.
See alsoPrint documents from your Mac