To add page number to any PDF output generated by the Email to PDF add-in, go to Outlook > PDF toolbar > Output Settings > Others tab and from the ‘Add PDF header and footer information‘ section (outlined below), enable the option ‘Add Page Number‘.
You have 4 options to choose from for placing the page number against the PDF document – Top, Left, Right or Bottom.
For more information, refer to the product page at https://www.assistmyteam.com/email-to-pdf-for-outlook/