How to compress a PDF for email attachments
By PDFEditor.ae · Published
Know the real limit
Attachment limits differ between email providers and between the sender's and recipient's systems, and they apply to the whole message. Attachments are also encoded for sending, which makes them larger in transit than on disk. Leave headroom rather than aiming exactly at the limit.
Steps
- Remove duplicate or irrelevant pages from a copy.
- Run Compress PDF and note the saved size.
- Add up the sizes of every attachment in the message.
- If you can, send a test to yourself and open the received attachment.
When the total is still too big
- If the size is mostly photos or scans, resize the images and rebuild the PDF — lossless compression will not shrink them.
- Split a long document into parts and send them in separate emails, numbered "part 1 of 3".
- Use a file-sharing link your organisation approves, and check the recipient can open it without requesting access.
Practical example
Sending three reports? Budget for the message, not each file. List the attachments in the email body so the recipient can confirm they received all of them.
Why did the email bounce below the limit?
Encoding adds roughly a third to attachment size in transit, and the other attachments and message text count too.