Email providers and corporate gateways enforce hard size ceilings—often 10–25 MB per message. A single scan-heavy PDF can blow that budget. Reducing size is not always about maximum compression; it is about hitting a deliverable target while keeping text legible. Start with Compress PDF, then escalate only if you still exceed limits.
Typical attachment limits
- Gmail: about 25 MB per attachment for consumer accounts.
- Outlook / Microsoft 365: commonly 20–34 MB depending on tenant policy.
- Corporate SMTP relays: often 10 MB—always test with your IT team.
Compression ladder (least to most aggressive)
- Remove blank or duplicate pages with Remove PDF Pages.
- Run recommended compression in Compress PDF and compare file size vs readability.
- Downsample only image-heavy sections; keep text pages at higher fidelity.
- Split into Part 1 / Part 2 using Split PDF when content must stay high quality.
Before you compress
Export from Word or Excel to PDF instead of printing scans when possible. If you must scan, 150–300 DPI is enough for most email workflows; 600 DPI archives belong in cloud storage, not inboxes. See our quality-focused compression guide for deeper tuning.