Sending a file or document to someone over the Internet is easy if you attach it to an e-mail message. However, some users complain about receiving an “Operation Failed” Attachment message in Microsoft Outlook. You can’t attach a file to new emails or when sending attachments to someone on a Windows 10 computer. Some users encounter this error when they open an email sent to them that contains an attachment with a Microsoft Word document.
The following solutions depend on the cause of the problem and the version of your Microsoft Outlook client. If you’re not sure what the problem is, you can follow each method individually and see if it works for you.