Back to Blogs
Compress & Split PDFs for Email | Rune
emailcompressattachmentsfile size

Compress & Split PDFs for Email | Rune

Learn how to compress and split PDFs to meet email attachment limits. Send large documents without delivery failures.

•
2 min read

Email attachment limits are frustrating. Your 30MB PDF won't send, and compressing doesn't reduce it enough. The solution? Split it into smaller parts that fit within limits.

Email Attachment Limits

Different email providers have different limits:

Provider Attachment Limit
Gmail 25 MB
Outlook 20 MB
Yahoo Mail 25 MB
iCloud Mail 20 MB
Corporate email Often 10-20 MB

If your PDF exceeds these limits, it won't send—or worse, will fail silently.

Two Approaches

1. Compress the PDF

Reduce file size while keeping all pages. Good for moderate size reduction.

  • Works for slightly oversized files.
  • May reduce image quality.
  • Limited reduction for text-heavy PDFs.

2. Split the PDF

Divide into multiple smaller files. Good for large files.

  • Works for any file size.
  • Maintains full quality.
  • Requires sending multiple attachments.

When to Use Each

File Size Recommended Approach
25-35 MB Try compression first
35-50 MB Split into 2 parts
50-100 MB Split into 3-5 parts
100+ MB Split into many parts or use file sharing

How to Split for Email

  1. Open Rune's Split PDF.
  2. Upload your large PDF.
  3. Use "Split Every N Pages" to divide evenly.
  4. Choose N so each part is under the limit.
  5. Split and download.
  6. Attach parts to separate emails or use a consolidation approach.

Calculating the Split

Example: 45MB PDF, 50 pages, Gmail limit 25MB.

  • Approximate per-page size: 45MB ÷ 50 = ~0.9MB/page.
  • Pages per email: 25MB ÷ 0.9MB = ~27 pages.
  • Split every 25 pages (safe margin).
  • Result: 2 PDFs, each well under 25MB.

Sending Split Files

Option 1: Multiple Emails

Send each part as a separate email. Recipients reconstruct on their end.

Option 2: Numbered Parts

Name clearly: Report_Part1_of_2.pdf, Report_Part2_of_2.pdf.

For very large files, consider uploading to cloud storage and sharing a link instead.

Pro Tips

  • Check recipient limits: The sender limit AND recipient limit both matter.
  • Include instructions: Tell the recipient how many parts to expect.
  • Number files clearly: Make the order obvious.
  • Consider alternatives: For very large files, cloud sharing may be better.

Conclusion

Don't let email limits block your important documents. Use Rune's Split PDF to divide large files into email-friendly parts.

Related Articles

View All Posts