You see error 0x80040607 when trying to send an email with an attachment in Outlook. This error means your email size exceeds a configured limit. The limit is set by your email administrator or your mail service provider. This article explains how to identify the limit and successfully send your files.
Key Takeaways: Resolving the Attachment Size Limit Error
- File > Info > Properties > Attachments: Check the total size of all attachments before sending to identify if you are over the limit.
- OneDrive or SharePoint link: Upload large files to cloud storage and share a link instead of attaching the file directly.
- File > Options > Mail > Mailbox Settings: Locate your account settings to review server send and receive limits for your specific email account.
Understanding Email Size Limits
Error 0x80040607 is a sending restriction error. It blocks an email because its total size is larger than a maximum allowed value. This total includes your message text, formatting, and all attached files combined. The limit is not set by Outlook itself but by the mail server that handles your messages.
For Microsoft 365 or Exchange Server accounts, your organization’s administrator defines the maximum send size. Common limits are 10 MB, 25 MB, or 150 MB. For POP3 or IMAP accounts like Gmail or Yahoo, the limit is defined by your email service provider. Gmail’s limit, for example, is 25 MB for attachments. You must reduce your email’s total size to below this threshold to send it.
Steps to Fix the Attachment Size Error
Follow these steps to resolve error 0x80040607 and send your message.
- Check the total attachment size
In your unsent message, go to the File tab on the ribbon. Select Info. Click on the Properties button. In the Properties window, look at the field labeled “Attachments.” This shows the combined size of all files you have attached. - Compress large files before attaching
If you have documents, images, or PDFs, reduce their file size. For images, use an image editor to lower the resolution or save them in a compressed format like JPEG. For Office documents like Word or Excel, use the built-in File > Save As > More options and look for tools to reduce file size or compress pictures. - Use cloud storage sharing
Upload the large file to a service like OneDrive, SharePoint, or Google Drive. In Outlook, with your new email open, go to the Insert tab. Click on Attach File and then browse cloud locations. Select the file and choose the “Share as Link” or “Attach as a Copy” option. Sharing a link does not count toward the email size limit. - Split attachments across multiple emails
If you must send the files directly, split them into smaller groups. Send two or three emails, each with a portion of the total files, ensuring each email stays under the size limit. Inform your recipient in the first email that more files are coming. - Verify your account’s send limit
Go to File > Account Settings > Account Settings. Double-click your email account to open its settings. In the Change Account window, note the Server Information. You may see a note about send/receive limits. For exact limits, contact your IT department or check your email provider’s support website.
If the Error Persists After Reducing Size
Outlook still shows the error after compressing files
Your email may still include hidden formatting or previous attachment data. Create a brand new email. Do not use Reply or Forward. Manually type the recipient’s address and message. Attach your compressed files to this fresh message and try sending it.
The sent email is stuck in the Outbox
If the error appears and the message is stuck, you must delete it from the Outbox. Go to your Outbox folder. Right-click the problematic message and select Delete. Then, follow the steps above to create a new, smaller message. Do not try to resend the stuck item.
You need to send a file larger than your server’s hard limit
If your file is 100 MB but your server limit is 25 MB, cloud sharing is the only direct solution. For internal recipients on the same Exchange server, your administrator may have set a higher internal limit. Contact IT to confirm if larger internal sends are allowed.
Attachment Methods Comparison
| Item | Traditional File Attachment | Cloud Link Sharing |
|---|---|---|
| Impact on email size limit | Uses full file size against your quota | Uses only link text, negligible size |
| Recipient action to view | Open attachment directly | Click link, may require sign-in |
| File size flexibility | Limited by server send limit | Limited by cloud storage, often much higher |
| Version control | File is static copy | Link can point to updated file |
| Security | File travels through email | File stays in controlled cloud location |
You can now identify and work within your email size limits to avoid error 0x80040607. Use the Properties window to check sizes before sending any email with attachments. For routine large file transfers, set up a OneDrive folder and use the Share Link feature directly from the Outlook ribbon. A useful advanced tip is to create a Mail Flow rule in Outlook if you are an administrator, which can automatically reject oversized messages before they reach a user’s Outbox.