The Problem with Large PDF Email Attachments
Email remains one of the primary ways we share documents, but large PDF attachments create significant problems for both senders and recipients.
Email Attachment Size Limits
Most email providers impose strict attachment size limits:
Gmail: 25 MBOutlook/Microsoft 365: 20 MBYahoo Mail: 25 MBApple iCloud Mail: 20 MBCorporate email: Often 10-15 MBThese limits apply to the total size of all attachments in a single email, and email encoding (Base64) increases the attachment size by approximately 33%.
Why Large Attachments Cause Problems
For Senders
Bounce backs: Emails exceeding size limits fail to sendSlow upload: Large files take longer to attach and sendStorage limits: Large sent items consume mailbox quotaUnreliable delivery: Large emails are more likely to be flagged or delayedFor Recipients
Slow download: Large attachments take longer to download, especially on mobileStorage consumption: Each large email uses significant mailbox spaceMobile data usage: Downloading large attachments uses mobile dataSynchronization delays: Email clients take longer to sync large mailboxesHow to Fix Large PDF Email Issues
Solution 1: Compress the PDF
The simplest solution is to compress the PDF before attaching it:
Visit Compressly's PDF compressorUpload your PDFDownload the compressed versionAttach the smaller file to your emailThis typically reduces PDF size by 30-70% while maintaining readability.
Solution 2: Reduce Image Quality in PDFs
If your PDF contains high-resolution images:
Reduce image resolution to 150 DPI for screen viewingUse JPEG compression for photographs within the PDFRemove unnecessary embedded imagesSolution 3: Split Large PDFs
For very large documents, consider splitting them into smaller sections:
Send separate emails for each sectionNumber the sections clearly in the subject lineInclude a table of contents in the first emailSolution 4: Use Cloud Sharing
For files that are still too large after compression:
Upload to Google Drive, Dropbox, or OneDriveShare a link instead of attaching the fileSet appropriate access permissionsInclude an expiration date if neededBest Practices for PDF Email Attachments
Always compress before sending: Make it a habit to compress PDFsCheck size after compression: Verify the file is under the limitUse descriptive filenames: Help recipients identify the contentMention the attachment in your email body: Prevent it from being overlookedConsider the recipient: Mobile users may prefer smaller filesPreventing Large PDFs in the First Place
Document Creation Tips
Use standard fonts instead of embedding custom onesOptimize images before inserting them into documentsAvoid unnecessary formatting and effectsRemove tracked changes and comments before converting to PDFUse the "Minimum Size" option when saving as PDFScanning Best Practices
Scan at 300 DPI for text, 150 DPI for screen-only documentsUse black and white mode for text documentsClean up scans to remove blank pages and unnecessary marginsApply OCR to keep file sizes manageableConclusion
Large PDF email attachments are a common frustration, but they're easily solvable. Compress your PDFs with Compressly before sending, and you'll avoid size limits while ensuring faster delivery.
Try Compressly's PDF compressor to reduce your PDFs for hassle-free email sharing.
Ready to Compress Your Files?
Try Compressly free - no signup required.