How to Compress PDF for Email: Beat Attachment Limits

“Your attachment is too large.” We’ve all seen this message when trying to email a PDF. Here’s how to compress your files to fit email limits.

Email Attachment Limits

Email Service	Attachment Limit
Gmail	25MB
Outlook.com	20MB
Yahoo Mail	25MB
iCloud Mail	20MB
ProtonMail	25MB
Corporate Exchange	10-25MB (varies)

Note: These are per-email limits. Multiple attachments share the limit.

Quick Solution

For most email attachments:

1. Target 8-10MB per PDF (leaves room for email overhead)
2. Use grayscale for text documents
3. Verify readability before sending

This works for 90% of email attachment needs.

Step-by-Step Guide

Step 1: Check Your File Size

On Mac:

1. Right-click the PDF
2. Select “Get Info”
3. Note the file size

Step 2: Determine Target Size

Your Limit	Target Size	Why
25MB	20MB	Leave buffer for email encoding
20MB	15MB	Same reason
10MB	8MB	Corporate limits need more margin

Email encoding adds ~33% overhead, so aim lower than the limit.

Step 3: Compress

Using SecureCompress:

1. Drop your PDF into the app
2. Set your target size
3. Click Start
4. Attach the compressed file to your email

Step 4: Verify

Before sending:

• Open the compressed PDF
• Check that text is readable
• Verify all pages are present

Scenarios and Solutions

Scenario 1: Single Large Document

Situation: 50MB contract needs to be emailed Limit: 25MB

Solution:

1. Compress to 20MB
2. Use grayscale if no color needed
3. Send as single attachment

Scenario 2: Multiple Documents

Situation: 5 documents totaling 80MB Limit: 25MB

Solutions:

Option A: Compress each document

• Compress each to ~4MB
• Send all in one email

Option B: Send multiple emails

• Group documents logically
• Keep each email under limit

Option C: Combine and compress

• Merge into one PDF
• Compress to 20MB
• Send as single file

Scenario 3: Photos/Scans

Situation: Scanned receipts at 100MB Limit: 25MB

Solution:

1. Compress to 20MB
2. Use grayscale (receipts don’t need color)
3. 150 DPI is sufficient for receipts

Alternative: Cloud Links

When compression isn’t enough:

When to Use Cloud Links

• File is still too large after compression
• Recipient needs original quality
• Multiple large files to share
• Ongoing collaboration needed

How to Share via Cloud

Google Drive:

1. Upload file to Drive
2. Right-click → Share
3. Copy link
4. Paste in email

Dropbox:

1. Upload file
2. Click “Share”
3. Copy link
4. Paste in email

iCloud:

1. Upload to iCloud Drive
2. Right-click → Share
3. Copy link

Pros and Cons

Method	Pros	Cons
Compressed attachment	Works offline, no account needed	Size limited
Cloud link	No size limit, version control	Requires account, link can expire

Tips for Specific Email Clients

Gmail

• 25MB limit is firm
• Large attachments auto-upload to Drive
• Recipients see Drive link instead

Outlook

• 20MB limit for Outlook.com
• Corporate limits vary (check with IT)
• OneDrive integration available

Apple Mail

• 20MB limit for iCloud
• Mail Drop for larger files (up to 5GB)
• Recipients get download link

Compression Settings for Email

Text Documents (Contracts, Reports)

Mode: Grayscale
DPI: 200
Target: 50-70% of original

Scanned Documents

Mode: Grayscale
DPI: 150-200
Target: 10-20% of original (scans compress well)

Documents with Photos

Mode: Color
DPI: 150
Target: 30-50% of original

Common Mistakes

Mistake 1: Compressing Too Much

Problem: Text becomes unreadable Fix: Increase target size, use grayscale instead of B&W

Mistake 2: Not Checking Before Sending

Problem: Recipient can’t read the document Fix: Always open and verify compressed file

Mistake 3: Forgetting Email Overhead

Problem: 25MB file rejected by 25MB limit Fix: Target 80% of the limit

Mistake 4: Re-compressing

Problem: Quality degrades with each compression Fix: Always compress from original

Professional Email Tips

For Business Documents

• Keep files under 10MB when possible
• Use descriptive filenames
• Mention file size in email body if large
• Offer to send via cloud if preferred

For Job Applications

• Compress resume to under 5MB
• Keep portfolio under 10MB
• Test by emailing to yourself first

For Legal Documents

• Verify all text is readable
• Keep original as backup
• Note compression in email if relevant

Mobile Compression

On iPhone/iPad

1. Use Files app to access PDFs
2. Share to a compression app
3. Save compressed version
4. Attach to email

On Android

1. Use file manager to find PDF
2. Share to compression app
3. Save and attach

Note: Mobile compression is less precise. For important documents, use desktop tools.

Troubleshooting

”File still too large”

1. Reduce target size further
2. Switch to grayscale
3. Lower DPI to 150
4. Consider cloud link instead

”Recipient says file is corrupted”

1. Re-compress from original
2. Try different compression settings
3. Test by emailing to yourself

”Quality is unacceptable”

1. Increase target size
2. Use cloud link for full quality
3. Split into multiple emails

Summary

To compress PDFs for email:

1. Know your limit (usually 20-25MB)
2. Target 80% of the limit
3. Use grayscale for text documents
4. Verify before sending
5. Use cloud links for very large files

Most documents can be compressed to fit email limits while remaining readable.

Download SecureCompress — hit your email attachment limits every time.