Reducing a PDF's size before emailing it

Keep the original PDF, then compress a copy only as much as the email limit requires. If the file contains large scans, those pages may offer the biggest reduction, but small text and diagrams must remain readable.

Open the exported file in another viewer. Check all pages, links, searchable text, images, and signatures before attaching it. If aggressive compression harms content, use a secure file-sharing method instead of forcing the PDF below the attachment limit.

What size limit must it meet?