How to Send Large Files via Email: Best Methods

You need to send a 50MB presentation to a client before a meeting that starts in an hour. You attach it to an email, hit send, and almost immediately get a bounce back: “Message size exceeds maximum allowed.”

Email attachment limits are frustrating, especially when you’re trying to share something quickly and be done with it. Most email providers cap attachments at 25MB, and some are even stricter. Trying to push large files through anyway fails, and it can even trip spam filters, slow delivery, or get your message blocked altogether. The solution is to use options that are actually meant for large file transfers.

This guide explains why email providers limit attachment sizes and how to send large files by email, using the approach that works best for you.

Why Sending Large Files via Email Is Difficult

Email providers enforce attachment size limits for technical and practical reasons that affect both senders and recipients. Typical attachment limits across providers include:

• Gmail: 25MB per message (attachments + email body)
• Outlook/Microsoft 365: 20MB for Outlook.com, up to 34MB for some enterprise accounts
• Yahoo Mail: 25MB per message
• Apple Mail/iCloud: 20MB via iCloud Mail Drop (larger files automatically convert to links)

These limits apply to the total message size, not individual attachments. If you attach three 10MB files, the combined 30MB exceeds most limits and causes delivery failure.

Reasons the email attachment size limits exist

These limits exist because of:

• Server storage constraints: Email servers store copies of every message and attachment. Allowing unlimited attachment sizes would overwhelm storage infrastructure and slow delivery for everyone.
• Network bandwidth: Large attachments take longer to upload and download, consuming bandwidth that affects server performance. During peak usage times, large files could create bottlenecks that delay all email delivery.
• Spam and malware prevention: Spammers and attackers often use large attachments to distribute malware or overwhelm recipients’ inboxes. Size limits help filter suspicious activity and reduce the volume of malicious content transmitted through email.
• Recipient inbox limits: Many email accounts have storage quotas. A single 100MB attachment could fill a significant portion of someone’s available space, especially on free email accounts with limited storage.

What happens when you exceed attachment limits

When exceeding these limits, expect:

• Immediate bounce: Your email typically bounces back with an error message like “message size exceeds maximum limit” or “attachment too large.” This is a hard bounce, meaning the message never reaches the recipient’s server.
• Delayed or partial delivery: Some email systems accept oversized messages but queue them for delayed delivery or strip attachments automatically, causing confusion when recipients receive incomplete messages.
• Spam filtering: Even if your message doesn’t immediately bounce, oversized attachments can trigger spam filters. Recipients might never see your email because it gets automatically filed into spam or junk folders.
• Sender reputation impact: Repeatedly sending messages that bounce or get filtered hurts your sender reputation over time. This affects future deliverability across all your emails, not just messages with large attachments.

How to Send Large Files Via Email

Instead of attaching large files directly, use one of three proven methods that keep files accessible without triggering size restrictions or delivery problems.

Use cloud storage

Cloud storage services provide the most reliable, flexible way to share large files via email. This method works for files of any size and gives you control over access permissions and sharing duration.

How cloud storage sharing works:

1. Upload your file to Google Drive, Dropbox, OneDrive, or another cloud storage service you already use or can access for free.
2. Generate a shareable link by right-clicking the file and selecting “Get link,” “Share,” or similar options depending on your provider.
3. Set permission controls to determine whether recipients can view only, comment, or edit the file. For most email sharing, view-only access is appropriate.
4. Copy the link and paste it into your email body. Write a brief explanation of what the file contains and any context the recipient needs.
5. Send the email with the link instead of an attachment. Recipients click the link to access and download the file from your cloud storage.

Why cloud storage is the best method:

• No size limitations. Cloud services handle files from kilobytes to gigabytes without delivery issues. A 500MB video or a multi-gigabyte dataset transfers just as easily as a 5MB document.
• Better control and security. You can revoke access to shared links at any time, set expiration dates, require passwords, or restrict downloads. This protects sensitive files better than email attachments that remain in recipients’ inboxes indefinitely.
• Reduced email delivery problems. Emails containing only links are smaller, faster to send, and less likely to trigger spam filters than emails with large attachments.
• Version control. If you update the file after sharing, recipients automatically see the latest version when they access the link. With email attachments, you’d need to send a new message for every update.

Available storage tiers

Most cloud providers offer free storage that’s sufficient for regular file sharing:

• Google Drive: 15GB free
• Dropbox: 2GB free (more with referrals)
• OneDrive: 5GB free (more with Microsoft 365 subscription)
• iCloud: 5GB free

Use a file transfer service

Dedicated file transfer services specialize in one-time sends where you don’t need permanent cloud storage. These services email download links to your recipients automatically.

How file transfer services work:

1. Upload your file to a file transfer service website.
2. Enter recipient email addresses in the form provided.
3. Add an optional message explaining what you’re sending.
4. Submit the transfer, and the service emails your recipients a download link that’s typically valid for 7-30 days.

Recipients receive an email from the service (not from you directly) with a link to download the file. After the expiration period, the file is automatically deleted from the service’s servers.

When file transfer services make sense:

• Large one-time sends: If you need to send a 2GB video file to someone once and don’t want to manage cloud storage permissions, transfer services handle everything automatically.
• No account setup required: Many services let you send files without creating an account. Enter the recipient’s email, upload, and send. No registration or ongoing management needed.
• Automatic expiration: Files delete themselves after a set period, which works well for temporary sharing where you don’t want files accessible indefinitely.

Limitations to consider:

• Less control: Once you submit a transfer, you typically can’t revoke access or change permissions until the link expires.
• Recipient confusion: Some recipients might be skeptical of download links from unfamiliar services, especially if they’re not expecting the file. Always send a separate email from your own address explaining that a file transfer is coming.
• File size limits on free tiers: Free versions often cap transfers at 2-5GB. Larger files require paid accounts.

Compress files before sending

File compression (zipping) reduces file sizes by encoding data more efficiently. This method helps when your files are slightly over attachment limits, but it won’t work for very large files.

How compression works:

1. Select files to compress on your computer.
2. Create a ZIP archive by right-clicking (Windows: “Send to → Compressed folder”; Mac: “Compress [filename]”).
3. Attach the compressed file to your email as you normally would.

Recipients download the ZIP file and extract it using built-in tools on any modern operating system.

What compression can realistically do:

• Text and document files compress well, often with a 50-70% reduction. A 40MB Word document might compress to 15MB, fitting under most email limits.
• Images and PDFs compress moderately, typically with a 10-30% reduction. A 30MB PDF might compress to 22MB.
• Videos, audio, and already-compressed formats barely compress at all, maybe 5% reduction. These file types are already encoded efficiently, so zipping them won’t create significant size savings.

When compression is appropriate

Use compression only when:

• Your files are just over the email limit (within 5-10MB of the cap)
• Files contain text, documents, or uncompressed images
• You’re comfortable asking recipients to extract ZIP files

When compression doesn’t work

Skip compression if:

• Files are significantly over limits (more than 10MB over)
• Files are already compressed (MP4 videos, MP3 audio, JPG images)
• Recipients might not know how to extract ZIP files

Choose the Right Method

Different scenarios call for different file-sharing approaches. Here’s how to decide quickly:

Use cloud storage when:

• Files are larger than 25MB
• You need ongoing control over who can access files
• Recipients might need the latest version of a file that gets updated
• You’re sharing with multiple people or teams
• File security and permission management matter

Use file transfer services when:

• You need to send a large file once with no follow-up
• You don’t want to manage cloud storage or permissions
• The file should automatically delete after a set time
• You’re comfortable with recipients downloading from a third-party service

Use compression when:

• Files are 5-10MB over your email provider’s limit
• Files contain uncompressed documents, text, or images
• You prefer traditional email attachments over links
• File sizes are small enough that compression brings them under limits

As a general rule, for anything over 25MB, default to cloud storage links. They’re universally supported, give you the most control, and work reliably for files of any size.

Best Practices to Avoid Email Delivery Problems

Beyond choosing the right file-sharing method, follow these practices to ensure your emails with file links get delivered reliably and don’t trigger spam filters.

Never attach large files directly

Even if you think your file is under the limit, sending large attachments repeatedly increases the chance of delivery problems. Email providers monitor sender behavior, and consistent use of maximum-size attachments can affect how they treat your messages. Over time, this pattern can signal inefficient sending practices and make your messages more likely to be delayed or filtered.

Clearly explain links in the email body

Don’t just paste a link without context. Recipients might ignore or delete unexplained links, thinking they’re spam or phishing attempts. Write a brief message explaining:

• What the file contains
• Why you’re sharing it
• What action you need from them (review, download, edit, etc.)

Example: “Hi Sarah, I’ve shared the Q4 budget proposal via Google Drive. You can access it here: [link]. Let me know if you have any questions or need edit access instead of view-only.”

Use clear, specific subject lines

Vague subject lines like “File” or “Document attached” trigger spam filters and don’t help recipients prioritize your message. Use descriptive subjects that explain what you’re sending. For example, instead of “File for you,” you can use “Q4 Budget Proposal – Ready for Review.”

Avoid spam trigger words and patterns

Even legitimate file-sharing emails can get filtered if they contain language commonly used in spam:

• Excessive capitalization or exclamation marks
• Words like “urgent,” “free download,” and “limited time”
• Multiple links to different domains
• Generic greetings like “Dear user”

Monitor your overall email health

File-sharing is just one part of maintaining good email deliverability. If you regularly send emails that bounce, get marked as spam, or go to invalid addresses, your sender reputation suffers across all messages, including those with file links.

To resolve email bouncing and maintain a clean email list, verify addresses before sending and use an email bounce rate calculator to track your delivery health over time. DeBounce helps you identify invalid, risky, and inactive addresses before they generate bounces that hurt your sender reputation.

When Email Isn’t the Best Channel

Some file-sharing scenarios require tools specifically built for the task rather than trying to adapt email for purposes it wasn’t designed to handle.

Extremely large files (10GB+)

While cloud storage handles files this large, sharing them via email links might not be ideal. Consider:

• Direct file transfer tools for enterprise needs
• Physical hard drives for multi-terabyte datasets
• FTP servers or dedicated file servers with proper access controls

Sensitive or confidential data

Email, even with cloud links, isn’t the most secure channel for highly sensitive information like:

• Financial records subject to compliance requirements
• Medical data covered by privacy regulations
• Legal documents requiring audit trails
• Intellectual property requiring strict access controls

For these scenarios, use:

• Secure file transfer protocols (SFTP)
• Enterprise content management systems with encryption
• Dedicated secure sharing platforms designed for your industry

Guaranteed delivery requirements

Email delivery isn’t guaranteed, even when following best practices. If you absolutely must confirm that files were received and accessed:

• Use platforms with read receipts and access logs
• Require recipient confirmation via separate channels
• Set up automated reminders for critical file reviews

Collaborative workflows requiring versioning

If multiple people need to edit files simultaneously with full version history and change tracking, email-based sharing becomes inefficient. Use:

• Google Workspace or Microsoft 365 for collaborative editing
• Version control systems (Git) for code and technical documentation
• Project management platforms with built-in file management

Understanding when to use email versus a dedicated file-sharing infrastructure helps you choose the most reliable, secure method for each situation.

The Bottom Line

Email attachment limits exist for good technical reasons, and trying to bypass them by forcing large files through email causes bounces, delays, and delivery problems. The reliable solution is working with email’s design rather than against it: upload large files to cloud storage, share links instead of attachments, and reserve file transfer services or compression for specific use cases.

Cloud storage links handle files of any size, give you control over permissions and access duration, and ensure your emails remain small and deliverable. For most file-sharing needs, this is the fastest and most flexible approach.

Set up a cloud storage account if you don’t already have one. Upload your next large file to Google Drive, Dropbox, or OneDrive, generate a shareable link, and send that link via email instead of attaching the file directly. You’ll immediately avoid size limits and improve delivery reliability.

Beyond individual file-sharing decisions, maintaining overall email health ensures your messages reach recipients reliably every time. Use DeBounce to verify your email lists, monitor ongoing deliverability, and catch issues before they generate bounces that hurt your sender reputation. Register now to verify your first addresses and start building stronger email practices, or explore email list monitoring to automatically track list quality over time.