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How to Send a Large PDF by Email: 6 Ways to Get Under the Limit
6 min readUpdated October 7, 2026By the PDF Studio team
“Message size exceeds limit” is a frustrating way to end a deadline. Email providers cap attachment sizes, and PDFs — especially scans — blow through those caps easily. Here is how much room you actually have and six ways to fit under it.
Know your real limit
Most mail services cap a message at roughly 20 to 25 MB, and some corporate systems set it much lower. The catch is that email attachments are encoded for transport, which makes them about one third larger than the file on disk. A 20 MB PDF can therefore become a 27 MB message and be rejected by a 25 MB limit. As a rule of thumb, aim for under 15 MB to be safe, and under 5 MB for recipients who use older or restricted systems.
Check the file size in your file manager first, so you know how far over the limit you are.
1. Compress the images
Large PDFs are almost always large because of images. Compress PDF recompresses JPEG images at lower quality and scales down oversized ones. Scans and photo-heavy files often shrink a lot; text-only PDFs barely change. Read how to compress a PDF without losing quality for what to expect.
2. Remove pages you do not need
Cover sheets, blank scanned backs, duplicate pages, and appendices the recipient does not need all add weight. Delete PDF Pages shows a thumbnail of every page so you can remove them at a glance.
3. Send only the pages that matter
If the recipient needs one chapter or a few exhibits, do not send the whole book. Extract Pages pulls selected pages or ranges into a new, smaller PDF. This is also better for privacy: they receive only what they need.
4. Split the file into parts
When everything has to be sent, divide it. Split PDF can cut a document by page ranges — for example “1-40, 41-80, 81-120” — into separate files that each fit under the limit. Name the parts clearly (Part 1 of 3) and send them in separate emails.
5. Fix the source before it becomes a PDF
If you are making the PDF from scans or phone photos, scan at 150 to 200 DPI in grayscale instead of 300 DPI in color: the file can be many times smaller with no loss in readability for text. Scan to PDF can fit images to standard pages and convert them to grayscale. Our guide to turning photos into a PDF explains the settings.