How do I save campaigns as PDF file?

There is currently no direct function for saving the mailing as PDF via the software.
There are two alternative options for saving and printing the mailing:
1) You can use the report for example Take a screenshot of the presentation, save it as a PDF and print it.

2) Via Mailings> Sent, you can duplicate all sent newsletters again at any time. then use the web version to save the newsletter as a PDF or print it out.