Will this work with every email provider?

We prepare file size. Delivery still depends on each provider’s attachment rules and policies.

Compress PDFs for email attachments

Mail systems often reject large attachments. UnderLimit helps you shrink PDFs toward a practical target while watching readability—especially for scans.

Drop up to 20 PDFs here

Max 150 MB per file · 500 MB total

Files are scanned before analysis.

Target

Mode

Attachment constraints

Provider limits differ. When in doubt, aim lower (for example 5 MB or 10 MB) or use a ZIP of multiple prepared files after compression.

Keep the message readable

Invoices and contracts should remain legible. Prefer Preserve/Balanced; use Strong only when analysis shows you still exceed the limit.

Several attachments

Compress a batch of PDFs, download them, then attach what you need—or share a ZIP when that fits your workflow.

FAQ

Will this work with every email provider?: We prepare file size. Delivery still depends on each provider’s attachment rules and policies.