"File exceeds the maximum attachment size." Every provider has a ceiling, and scanned PDFs hit it constantly — a 300-dpi color scan runs 1–3 MB per page, so a 30-page scan easily lands north of 40 MB.
The limits, current as of 2026
| Provider | Sending limit | Notes |
|---|---|---|
| Gmail | 25 MB | Larger files auto-convert to a Google Drive link |
| Outlook / Microsoft 365 | 20 MB | Exchange servers often cap lower (10 MB is common) |
| iCloud Mail | 20 MB | Mail Drop links up to 5 GB |
| Yahoo Mail | 25 MB | |
| Corporate mail servers | often 10 MB | The real-world bottleneck — receiving servers reject, too |
Two traps worth knowing: attachments are Base64-encoded, which inflates them ~33 % in transit (a 19 MB file can bounce off a 25 MB limit), and the recipient's server can reject what yours allowed. If a document matters, staying under 10 MB per message is the only safe assumption.
Option 1: Split the PDF into parts
The most reliable fix, because it needs nothing from your recipient — no Drive permissions, no expiring links, no "please request access."
- Drop the PDF on the PDF splitter.
- Choose Every N pages. For a 60-page, 45 MB scan, splitting every 15 pages yields four parts around 11 MB each; drop to every 10 pages if you need to duck under 10 MB.
- Download the ZIP, then attach the parts across two or three messages, labeled "Part 1 of 3" in the subject line.
Since page sizes vary (a page with a full-bleed scan weighs far more than a text page), check the actual part sizes and adjust N rather than assuming even division.
Option 2: Send only the pages that matter
Attachment bloat is often unnecessary pages, not an unavoidably big document. Does the recipient need the whole 90-page agreement, or the signature page and two exhibits? Extract just those pages and you're usually under any limit in one message.
Option 3: A link instead of an attachment
Drive, Dropbox, and Mail Drop links bypass limits entirely — at the cost of new failure modes: permissions, expiry, corporate link-blocking, and the document living on a third-party server. For sensitive files, a split attachment keeps the document inside the mail system your organization already trusts.
Why not just compress it?
ZIP compression barely touches scanned PDFs — the images inside are already JPEG-compressed, so zipping typically saves single-digit percentages. Recompressing the images does shrink the file but visibly degrades quality and re-renders the document. Splitting keeps every page at original quality; it just changes how the pages are packaged.
The splitter runs entirely in your browser, so even that confidential 45 MB scan never touches a server on its way to becoming three attachable parts.