If you can’t attach files in Gmail or are seeing error messages as “Attachment failed. This may be due to a proxy or firewall” while trying to do so, we’ll guide you step-by-step to get your Gmail attachments working smoothly again.

Why Can’t I Attach Files in Gmail?

Before you try to fix attachment failed issues in Gmail, it’s important to understand why you may encounter this problem.

While a firewall or proxy server can be the cause, other factors might prevent you from attaching files to your emails or the Gmail attachment button from working.

Here are some possible reasons why you can’t attach files in Gmail:

  • If you’re trying to send an executable file, Gmail may be blocking it as a security measure to prevent the spread of viruses.
  • Gmail has specific file size limits for attachments. If your file exceeds the allowed size (up to 25MB), you won’t be able to attach it.
  • Gmail supports various file formats, but some uncommon or restricted formats may not be attachable.
  • In other cases, the problem is with the user’s browser. One of your browser extensions may be limiting the functionality of Gmail.
  • Certain browser settings, such as pop-up blockers or security settings, might prevent you from attaching files in Gmail.
  • A firewall or proxy server may be blocking the attachment function in Gmail.
  • Unstable or slow internet connections can disrupt the attachment process and lead to failure.
  • If your Gmail storage is full, you won’t be able to attach additional files until you free up space.
  • Accumulated cache and cookies in your browser may affect the functionality of Gmail’s attachment feature.
  • Another reason why you can’t attach files in Gmail because your browser does not support the email service. If you want to access the best experience, opt for supported browsers like Edge, Chrome, Safari, and Firefox.

Also Read: What is the Best Internet Browser?


How to Fix the “Can’t attach files in Gmail” Error?

Here are some fixes and steps for each to help resolve the “Can’t attach files in Gmail” issues:

Fix 1: Check file size limitations

  • Ensure that the file you are trying to attach does not exceed Gmail’s attachment size limit. For standard Gmail accounts, the current limit is 25 MB.
  • If the file is too large, consider compressing it into a ZIP file or using cloud storage services like Google Drive.

Fix 2: Verify supported file formats

  • Confirm that the file format is supported by Gmail. Common file types such as documents, images, and videos are usually compatible.
Currently, the file types blocked by Gmail are:
.ade, .adp, .apk, .appx, .appxbundle, .bat, .cab, .chm, .cmd, .com, .cpl, .diagcab, .diagcfg, .diagpack, .dll, .dmg, .ex, .ex_, .exe, .hta, .img, .ins, .iso, .isp, .jar, .jnlp, .js, .jse, .lib, .lnk, .mde, .msc, .msi, .msix, .msixbundle, .msp, .mst, .nsh, .pif, .ps1, .scr, .sct, .shb, .sys, .vb, .vbe, .vbs, .vhd, .vxd, .wsc, .wsf, .wsh, .xll
  • Convert the file to a supported format or try compressing it if necessary.

Fix 3: Check your Gmail storage

  • Log into Gmail.
  • Locate and click on the gear icon in the top-right corner.
  • Select Settings from the drop-down menu
  • Go to Storage
  • On the Storage tab, you will see the total storage available for your Gmail account and the storage used.
  • Click Manage or Buy more storage to review options for increasing your storage capacity or deleting unnecessary emails or attachments.

Fix 4: Turn off your firewall

  • Press Windows Key + R on your keyboard to launch the Run dialog box.
  • Inside the Run dialog box, type firewall.cpl, then hit Enter.
  • Go to the left-pane menu, then click Turn Windows Defender Firewall on or off.
We recommend switching you firewall off temporarily
  • Under Domain, Private, and Public Network Settings, select the Turn off Windows Defender Firewall option.
Select the ‘Turn off Windows Defender Firewall’ option
  • Once you’ve selected the right option, click OK and close the window.

Related: How to Check Firewall Settings in Windows 10 PC


Fix 5: Disable your proxy server

  • Press Windows Key + S on your keyboard to bring up the search bar.
  • Type Internet options, then select Internet Options from the results.
  • Go to the Connections tab, then click LAN Settings.
Try disabling your proxy server to see if it fixes the issue
  • On the Local Area Network (LAN) Settings window, deselect the Use proxy server for your LAN option.
deselect the ‘Use proxy server for your LAN’ option
  • Click OK on the LAN Settings window, then click Apply and OK on the Internet Properties window.

Fix 6: Clear your browser cache and cookies

If the problem concerns your browser, then clearing your cache and cookies may do the trick.

Cookies are automatically generated whenever you visit a website. They store your browsing data and are supposed to improve your browsing experience.

Meanwhile, the browser cache remembers portions of web pages, such as images. Thus, the next time you visit a website, the pages will load faster.

Over time, cache and cookies accumulate and overwhelm your browser.

So, you need to clean them regularly. If you’re using Google Chrome, here are the steps you need to take:

  • Launch Google Chrome.
  • Click the three vertical dots in the top right corner.
  • From the drop-down, select Delete Browsing Data.
Chrome Delete Browsing Data
  • Select All Time under the drop-down list for Time Range.
Chrome Delete Browsing Data All Time
  • Click the Cookies and other site data and Cached images and files options.
  • Click Delete Data.

Fix 7: Update your web browser to the latest version

If you use Google Chrome, follow these steps to update the Chrome browser:

  • Click the three vertical dots in the top-right corner.
  • Navigate to Help > About Google Chrome.
  • Chrome will automatically check for updates and install them if available.
  • After the update is complete, reload the page to restart Chrome with the latest version.

Also Read: Ultimate Guide: How to Reset the Google Chrome Browser to Its Default Settings?


Fix 8: Disable any browser extensions or add-ons

If you have several extensions or add-ons, one or two of them could affect Gmail’s functionality. Try disabling them one by one to check which extension might be causing the problem of being unable to attach files in Gmail.

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Fix 9: Go Incognito

If a browser extension prevents you from attaching files to your emails, here’s a solution: you can go incognito and sign into your Gmail account.

Once you’ve opened your Gmail account in an incognito window, try sending an email with an attachment again. If the problem persists, try the next method.

Fix 10: Check Internet connectivity

  • Make sure you have a stable and reliable internet connection.
  • Try switching to a different network or restarting your modem/router if necessary.

Fix 11: Check your system for Malware

Check your system for malware:

  • Run a thorough scan of your computer using reputable antivirus or anti-malware software like Auslogics Anti-Malware.
  • Remove any detected malware or potentially harmful programs that may be interfering with Gmail’s functionality.

Also read: Auslogics Anti-Malware: Features and Reviews


Fix 12: Update your drivers

Did you try attaching a file stored in an external drive? If so, there may be something wrong with your storage device.

If you have outdated drivers, you may be unable to successfully attach files from your drive.

In this case, the best solution is to update your drivers to the latest versions recommended by the manufacturer.

You can do this manually, but the process can be tedious and risky.

First, you must go to the manufacturer’s site and search for the driver version compatible with your operating system and processor type.

If you download and install the wrong driver, you may cause bigger problems for your PC.

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As such, we recommend skipping all the hassle by automating the process. If you want a quick and safe way to update your drivers, use Auslogics Driver Updater instead.

All you need to do is click a button, and the tool will automatically scan your system and search for compatible drivers.


Also read: How to Check if My Drivers Are Up to Date on Windows 10 PC?


Fix 13: Try Using Gmail in a Different Browser or the Gmail Mobile App

It wouldn’t hurt if you tried attaching files to your email using the other browser (Gmail supports Safari, Chrome, Firefox, Edge, and Internet Explorer) or mobile version of Gmail.

Conclusion

Go through the guide and choose the solution that works for you. If this article was helpful, share with your friends and colleagues, and let us know if any additional thoughts you know.

FAQ

To attach an email in Gmail, follow these steps:

  • Click on the Compose button to start a new email.
  • Locate the email you wish to attach in your Gmail inbox or any other folder.
  • Click and hold the email you want to attach, then drag it into the new email composition window. You can drop it anywhere within the email or specifically in the designated attachment area.
  • Once you release the mouse button, Gmail will upload and attach the email to your new email composition. You’ll see the email attached as a separate file or icon within the email.

  • Open Gmail and compose a new email.
  • Click the Google Drive icon in the email composition window.
  • Select the Google Doc you want to attach.
  • Click Insert or Insert as attachment to add the document to the email.

  • Compress the folder into a ZIP file: Right-click on the folder you want to attach, select Send to, and choose Compressed (zipped) folder from the options. This will create a ZIP file containing the entire folder.
  • Open Gmail and compose a new email
  • Click the Attach files button (paperclip icon) in the email composition window.
  • Select the ZIP file you created in step 1 from the file explorer or drag and drop the ZIP file directly into the email composition window.

  • File size limit: Check if the file exceeds Gmail’s 25 MB limit.
  • Unsupported format: Ensure the file is in a supported format.
  • Browser issues: Update your browser and disable incompatible extensions.
  • Internet connectivity: Check your internet connection for stability.
  • Storage space: Free up space in Gmail by deleting unnecessary emails or attachments.
  • Clear cache and cookies: Remove accumulated browser data that may affect attachment functionality.

Here’s how to send a video through Gmail:

  • Reduce the video’s file size by compressing it: use video compression software or online tools. 
  • Upload the video to a cloud storage service like Google Drive, Dropbox, or OneDrive. Once uploaded, generate a shareable link.
  • Compose a new email in Gmail and insert the shareable link of the video into the body. Then, provide instructions for the recipient to access and download the video.

The Gmail file size limit is the maximum file size that you can attach to an email when using Gmail. The Gmail email size limit is currently set to 25 megabytes (MB) for standard Gmail accounts.

This means that any file you wish to attach to an email in Gmail should not exceed this size.