How To Send A Big File On Outlook : Large Attachment Sending Solution

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Sending a large file through Outlook often fails until you learn the right method. Many users struggle with email size limits, but knowing how to send a big file on Outlook can save you time and frustration. This guide covers every practical solution, from built-in features to third-party tools.

Outlook has a default attachment limit of 20 to 34 megabytes, depending on your version. Exceed that, and your email bounces back or gets stuck in the outbox. Let’s fix that.

Why Outlook Blocks Large Attachments

Email servers have strict size caps to prevent overload. Microsoft Exchange servers typically allow 10 MB to 25 MB per message. Gmail and Yahoo have similar limits. When you try to send a 50 MB video file, the system rejects it.

You can’t bypass this by compressing files alone. A 100 MB folder zipped to 80 MB still exceeds most limits. You need alternative methods.

How To Send A Big File On Outlook

This section covers the most reliable ways to share large files through Outlook. Each method works for different scenarios, so pick the one that fits your needs.

Method 1: Use OneDrive Integration

Outlook integrates directly with Microsoft OneDrive. This is the easiest solution if you have a Microsoft 365 subscription or a free OneDrive account.

  1. Open a new email in Outlook.
  2. Click the “Attach File” icon in the ribbon.
  3. Select “Browse this device” or “Browse cloud locations.”
  4. Choose the file from your computer or OneDrive folder.
  5. If the file is large, Outlook automatically offers to upload it to OneDrive and share a link instead of attaching the file directly.
  6. Click “Share as OneDrive link” when prompted.
  7. Set permission levels: “Recipients can edit” or “View only.”
  8. Send the email. The recipient gets a download link, not the actual file.

This method works for files up to 2 GB with a free OneDrive account. Paid plans allow up to 100 GB per file. The link expires after a set time, which you can adjust in OneDrive settings.

One downside: the recipient needs internet access to download the file. Also, if they don’t have a Microsoft account, they might face login prompts. You can change sharing settings to “Anyone with the link” to avoid this.

Method 2: Compress Files Before Attaching

Compression reduces file size, but it’s not magic. Use this method for moderately large files like a 15 MB PDF or a 25 MB image folder.

  1. Right-click the file or folder on your computer.
  2. Select “Send to” then “Compressed (zipped) folder.”
  3. A new ZIP file appears in the same location.
  4. Attach the ZIP file to your Outlook email.

For better compression, use third-party tools like 7-Zip or WinRAR. They can shrink files more than Windows’ built-in tool. For example, a 30 MB PowerPoint file might compress to 10 MB with 7-Zip.

Remember: compression works best on text-heavy files like documents and spreadsheets. Videos, images, and already-compressed files like MP3s won’t shrink much.

If the compressed file is still over 25 MB, you need another method.

Method 3: Use A File Transfer Service

When OneDrive isn’t an option, third-party services work well. These tools upload your file to their servers and generate a download link you paste into your Outlook email.

Popular options include:

  • WeTransfer: Free for files up to 2 GB. No account required.
  • Dropbox Transfer: Free for files up to 100 MB. Paid plans go to 100 GB.
  • Google Drive: Free 15 GB storage. Share links directly.
  • SendAnywhere: Free for files up to 10 GB. Links expire after 48 hours.

Steps for WeTransfer (similar for others):

  1. Go to wetransfer.com.
  2. Click “Transfer” and select your file.
  3. Enter your email and the recipient’s email.
  4. Write a short message (optional).
  5. Click “Transfer.” The service uploads your file.
  6. Copy the download link provided.
  7. Paste the link into your Outlook email body.
  8. Send the email.

These services are secure for most purposes. Avoid sending sensitive data like bank statements or passwords through free services. Use encrypted options like Tresorit Send for confidential files.

Method 4: Split Large Files Into Smaller Parts

If you must attach files directly and compression isn’t enough, split the file into smaller chunks. This is old-school but works.

  1. Use a file splitter tool like WinRAR, 7-Zip, or GSplit.
  2. Choose a split size, for example, 20 MB per part.
  3. The tool creates multiple files: file.zip.001, file.zip.002, etc.
  4. Attach each part to a separate email.
  5. Send all emails to the same recipient.
  6. Instruct the recipient to use a joiner tool to reassemble the file.

This method is tedious. You send multiple emails, and the recipient must combine them. Only use this when other options fail.

Method 5: Use Outlook’s Large File Sharing Feature (Exchange Online)

If you use Microsoft 365 with Exchange Online, Outlook has a built-in large file sharing feature. It’s similar to OneDrive integration but more automatic.

  1. Open a new email.
  2. Click “Attach File.”
  3. Select the large file from your computer.
  4. Outlook detects the file size and prompts: “This file is too large. Would you like to upload it to OneDrive and share a link?”
  5. Click “Yes.”
  6. Set permissions as needed.
  7. Send the email.

This feature is seamless. The recipient sees the file as an attachment, but it’s actually a link. They click it and download from OneDrive. No extra steps for them.

Method 6: Use A VPN Or Change Network Settings

Sometimes the issue isn’t file size but network restrictions. Corporate networks often block large uploads. Try these steps:

  • Use a VPN to bypass network limits.
  • Connect to a different Wi-Fi network.
  • Use your mobile hotspot.
  • Upload the file from a different location.

This doesn’t change Outlook’s attachment limit, but it can fix upload failures caused by network throttling.

Common Mistakes When Sending Large Files

Avoid these errors to ensure successful delivery:

  • Attaching the file directly without checking size.
  • Forgetting to set OneDrive link permissions. Recipients might not be able to access the file.
  • Sending multiple large attachments in one email. Even if each file is under 25 MB, the total might exceed limits.
  • Using email compression that degrades file quality. For images, use lossless compression.
  • Not informing the recipient about the file transfer method. They might not recognize the download link.

How To Check Outlook’s Attachment Size Limit

Knowing your specific limit helps you plan. Here’s how to find it:

  1. Open Outlook.
  2. Go to “File” > “Options.”
  3. Click “Mail.”
  4. Under “Send messages,” look for “Maximum message size.”
  5. If you don’t see this option, your limit is set by your email server.

For Exchange accounts, ask your IT admin. For personal accounts like Outlook.com, the limit is 34 MB. For Gmail, it’s 25 MB. For Yahoo, it’s 25 MB.

Best Practices For Sending Large Files

Follow these tips to avoid problems:

  • Always use a link-sharing method for files over 20 MB.
  • Compress files before uploading to save time.
  • Set expiration dates on shared links to maintain security.
  • Use password protection for sensitive files.
  • Test the download link yourself before sending.
  • Inform the recipient about the file size and download steps.

What To Do If The Recipient Can’t Download

Sometimes the download fails. Here are common fixes:

  • Check if the link expired. Regenerate it.
  • Verify the recipient has permission. Change sharing settings to “Anyone with the link.”
  • Ask the recipient to try a different browser or device.
  • Clear browser cache and cookies.
  • Disable ad blockers that might interfere.
  • Try a different file transfer service.

Security Concerns With Large File Sharing

Large files often contain sensitive data. Protect yourself:

  • Use encrypted transfer services like Tresorit or Sync.com.
  • Never send passwords in the same email as the file link.
  • Use Outlook’s “Encrypt” feature for sensitive emails.
  • Delete files from the cloud after the recipient downloads them.
  • Avoid public Wi-Fi when uploading confidential files.

Frequently Asked Questions

What is the maximum file size I can send in Outlook?

For Outlook.com, the limit is 34 MB. For Microsoft 365 with Exchange Online, the default is 25 MB, but admins can increase it to 150 MB. For Outlook desktop, it depends on your email server.

Can I send a 100 MB file in Outlook?

Yes, but not as a direct attachment. Use OneDrive integration or a file transfer service like WeTransfer. These methods allow files up to 2 GB or more.

Why does my large file attachment fail in Outlook?

Common reasons: file exceeds server limit, network timeout, corrupted file, or permission restrictions. Try compressing the file or using a link-sharing method.

Does Outlook compress attachments automatically?

No, Outlook does not compress attachments. You must compress files manually using a tool like 7-Zip before attaching them.

Is it safe to send large files through Outlook?

It depends on the method. Direct attachments are safe but limited. OneDrive links are secure if you set proper permissions. Third-party services vary; use encrypted options for sensitive data.

Final Tips For Success

Test your method before sending important files. Send a test email to yourself first. Check if the attachment or link works. Adjust permissions if needed.

Keep your Outlook and OneDrive updated. New features often improve file sharing. For example, Microsoft recently increased OneDrive file size limits for business accounts.

If you frequently send large files, consider upgrading to Microsoft 365 Business. It offers larger attachment limits and better integration with SharePoint and Teams.

Remember, the key to sending large files is to avoid direct attachments. Use cloud storage links or file transfer services. This saves time, reduces errors, and keeps your emails professional.

Now you know how to send a big file on Outlook without frustration. Choose the method that works for your situation and start sharing files smoothly.