Save an Outlook message as a PDF file

Outlook doesn't include PDF as one of the default Save as types. The Microsoft Print To PDF utility included in Windows 10 allows you to print any email message directly to a PDF.

Save as (or Print to) a PDF in Windows 10

Open the message you want to save, and on the File tab, click Print.
From the Printer drop-down, choose Microsoft Print to PDF.
Choose Print.
In the Save Print Output As box, choose a folder for your PDF and enter a file name. Then choose Save.