Answer
Use the PDF_REPORT_CREATED event instead of relying on the standard Print-window 'Send email to' action — that built-in action uses fixed, non-customizable email content, but PDF_REPORT_CREATED lets you build a custom event that controls the email body, subject, and other details as needed, since it fires whenever a report's PDF has been generated. See IFS's documentation on emailing reports for the specific setup steps for this event-based approach.