Gmail Attachment Failed Error — What It Means & How to Fix It

What Does This Error Mean?

Gmail's "Attachment failed" error means the file you tried to attach could not be uploaded to Google's servers. This can happen because the file is too large, your internet connection dropped mid-upload, the file type is blocked, or there is a temporary problem with Gmail itself. Most attachment failures are easy to fix once you know the cause.

Affected Models

Gmail in Google Chrome
Gmail in Firefox
Gmail in Safari
Gmail on Android
Gmail on iPhone

Common Causes

The file is larger than Gmail's 25 MB attachment limit
Your internet connection was slow or interrupted during the upload
The file type is blocked by Gmail for security reasons (such as .exe files)
A browser extension is interfering with the file upload process
Gmail is experiencing a temporary server problem

How to Fix It

Check the file size. Gmail's attachment limit is 25 MB per email. Right-click the file and choose Properties to see its size.

If the file is over 25 MB, use the Google Drive option in Gmail's compose toolbar instead. Drive can share files of any size.
Check the file type. Gmail blocks certain file types including .exe, .bat, .com, .cmd, .msi, and others that could contain malware.

If you need to share a blocked file type, put it in a ZIP folder first. Gmail allows .zip files.
Try uploading the file again with a stable internet connection. Avoid attaching large files on mobile data or weak Wi-Fi.

A slow or interrupted connection is a very common cause of failed uploads.
Open Gmail in an Incognito window and try attaching the file again.

Extensions — especially ad blockers — can interfere with Gmail's file upload feature.
Reload Gmail and try the attachment again. If the error persists, wait 10 minutes and try once more.

Temporary Gmail server issues usually clear up within minutes.

When to Call a Professional

Attachment errors do not require professional help. For files over 25 MB, use Google Drive to share the file instead — Gmail integrates directly with Drive. If your Gmail account is completely inaccessible, contact Google support at support.google.com.

Frequently Asked Questions

What is the maximum file size I can attach in Gmail?

Gmail allows attachments up to 25 MB per email. If your total attachments exceed that, Gmail will automatically suggest inserting them from Google Drive instead. Google Drive sharing has no meaningful size limit for most files.

Why can't I attach an EXE file in Gmail?

Gmail blocks executable file types (.exe, .bat, .com, etc.) as a security measure. These file types can contain malware. To share an executable, compress it into a .zip file first. Note: Gmail may still block .zip files that contain blocked types inside them.

My file is small but Gmail still says attachment failed. Why?

Small files can still fail if your connection drops during upload or if Gmail has a brief server issue. Also check that your Google Account storage is not full — go to one.google.com/storage to check. If your 15 GB of free storage is used up, Gmail cannot receive or send attachments.