How to Send Files That Are Too Big for Email

Why Email Has Attachment Size Limits

Email wasn't designed for large file transfers. The protocol dates back to the 1970s, and attachment support was bolted on later through MIME encoding. This encoding actually increases file size by about 33%, meaning a 20MB file becomes roughly 26MB when attached.

Here are the current limits for major email providers:

• Gmail: 25MB per message
• Outlook.com/Hotmail: 20MB per message
• Microsoft Exchange (business): 10MB default, up to 150MB if admin allows
• Yahoo Mail: 25MB per message
• Apple iCloud Mail: 20MB per message

When you hit these limits, your email simply won't send. You'll see an error like "attachment is too large" or "file exceeds the maximum size." This happens constantly when sharing videos, design files, or presentations.

The Fastest Solution: Share a Link Instead

Skip attachments entirely. Upload your file to cloud storage and share a download link instead. This works for files of any size and preserves original quality.

Here's why linking beats attaching:

• No size limits: Share files up to 250GB or more, depending on your service
• Faster delivery: Recipients download directly from the cloud, no relay through email servers
• Quality preserved: No compression, no quality loss
• Access control: Revoke access, add passwords, set expiration dates
• Version updates: Replace the file and the link stays the same

Most email providers now integrate cloud storage directly. Gmail offers Google Drive links, Outlook suggests OneDrive. But these built-in options often require recipients to have accounts or deal with permission requests.

With Fast.io, you upload once and share a direct link. Recipients click and download without creating an account or requesting permissions. You can password-protect links, set them to expire, or restrict downloads to specific email domains.

Method 1: Use Built-in Cloud Storage Links

Every major email provider offers a cloud storage integration. When you try to attach a file that's too large, the email client will usually suggest uploading to their cloud service instead.

Gmail with Google Drive

1. Click the compose button
2. Click the Google Drive icon in the toolbar (or try to attach a large file)
3. Upload your file or select one already in Drive
4. Choose "Drive link" (not "Attachment")
5. Set sharing permissions before sending

Google Drive links can share files up to 5TB. Recipients with Google accounts get a smoother experience, but anyone can download with the right permissions.

Outlook with OneDrive

1. Compose a new message
2. Click Attach > Upload and share
3. Select your file (OneDrive stores it automatically)
4. Recipients get a link instead of an attachment

OneDrive links support files up to 250GB. The integration works best when both sender and recipient use Microsoft accounts.

Method 2: Dedicated File Transfer Services

When you need more control than basic cloud links offer, dedicated file transfer services provide professional features like branding, analytics, and better security.

What to look for

• Large file support: At minimum 2GB free, ideally unlimited for paid plans
• No recipient account required: The person receiving the file shouldn't need to sign up
• Link controls: Password protection, expiration dates, download limits
• Delivery confirmation: Know when files are downloaded
• Speed: Fast upload and download without throttling

Popular options

• WeTransfer: Up to 2GB free, 200GB on paid plans. Files expire after 7 days on the free tier.
• Dropbox Transfer: Up to 250GB per transfer. Includes password protection and download tracking.
• Fast.io: No file size limits for team plans. Files don't expire, and you get full analytics on who accessed what.

The key difference between transfer services and basic cloud storage is workflow. Transfer services are designed for sending files out, not storing them long-term. Fast.io bridges both: your files live in organized workspaces, and you can share any file with a controlled link at any time.

Method 3: Compress Before Sending

Compression works when your file is just slightly over the limit. A 30MB PowerPoint might compress down to 22MB and slip under Gmail's 25MB cap.

How to compress files

On Windows: Right-click your file or folder and select "Send to" then "Compressed (zipped) folder"

On macOS: Right-click and choose "Compress"

On both: Download 7-Zip (Windows) or Keka (Mac) for better compression ratios

When compression helps

• Documents, spreadsheets, presentations (often compress 50-70%)
• Uncompressed images like BMP or TIFF
• Folders with many small files

When compression doesn't help

• Videos (MP4, MOV are already compressed)
• Images (JPEG, PNG, WebP are already compressed)
• PDFs (usually already optimized)
• ZIP files (can't compress what's already compressed)

If compression doesn't shrink your file enough, you're better off using a link-based method. Attempting to compress video files often wastes time and might corrupt the file.

Method 4: Split Files Into Parts

Splitting breaks a large file into smaller chunks that fit under the email limit. The recipient downloads all parts and reassembles them. It works, but it's a hassle for everyone involved.

How to split files

1. Download 7-Zip (free, Windows) or Keka (free, Mac)
2. Right-click your file, select "Add to archive"
3. Under "Split to volumes," enter a size like "20M" for 20MB parts
4. You'll get files named like: video.zip.001, video.zip.002, video.zip.003
5. Send each part in a separate email

Why splitting is usually not worth it

• Multiple emails required: Recipients get confused
• Assembly required: They need the same software to rejoin files
• One missing part breaks everything: If any email gets lost or filtered, the file can't be reassembled
• Time-consuming: Both sending and receiving take longer

Splitting made sense before cloud storage existed. Now it's a last resort for situations where you can't use any online service. For anything else, just share a link.

Which Method Should You Use?

The best approach depends on your file size and how often you send large files.

For occasional large files (under 2GB): Use your email's built-in cloud integration. Gmail with Drive, Outlook with OneDrive. It's already there and works for most situations.

For frequent large file sharing: Set up a dedicated service. If you're sending files multiple times a week, the time savings add up. Look for one that doesn't require recipients to create accounts.

For teams sharing with clients: Use a workspace-based solution like Fast.io. Files stay organized in one place, links are always shareable, and you get analytics on who downloaded what. No more hunting through email for "that file I sent you last month."

For extremely large files (10GB+): Most free services have limits. Fast.io handles files up to 250GB with HLS streaming for video, meaning recipients can preview before downloading.

Skip compression unless you're just a few MB over the limit. Skip splitting entirely. It's more trouble than it's worth. Linking is faster, more reliable, and gives you control over your files after you send them.