I’m trying to find a solution to block users from attaching files when using web email services like Gmail or Outlook online. My goal is to completely remove or disable the attachment button so files cannot be sent through these platforms.
I’ve been wondering if it’s possible to intercept system messages or modify the browser interface to hide the file selection dialog that appears when someone tries to upload a document. Has anyone successfully implemented something like this before?
Any suggestions on how to approach this problem would be really helpful. I’m open to different methods whether it involves browser extensions, system-level modifications, or other technical solutions.
you gotta manage this at the network lvl, not just in browser. Try setting up a proxy server or use firewall rules to block those file upload requests. I know some companies use Websense n stuff to restrict webmail features, but I haven’t done it myself.
Had this exact issue at my last job - we needed to stop people from sending files through email attachments. Here’s what actually worked: Set up a web application firewall with custom rules that block POST requests with multipart/form-data going to email domains. This catches the upload before it even hits the email interface. We also used our corporate proxy to inject JavaScript that removes file attachment elements when pages load. Pretty effective combo since it works regardless of browser or cache clearing. Just heads up - you’ll need to update your target selectors regularly because email providers change their HTML structure all the time. And test everything thoroughly since aggressive blocking can mess with other email features like pasting inline images.
From my past experience, an effective method to disable file attachments in web email clients is to use browser policies in conjunction with content filtering. Implementing Chrome or Edge enterprise policies via Group Policy can help disable the file upload dialogs entirely. Specifically, the “DefaultFileSystemWriteGuard” and “FileSystemWriteBlockedForUrls” policies are useful for preventing file operations on targeted domains. For a quicker solution, consider using browser extensions like uBlock Origin with custom filters that can hide attachment buttons. However, be aware that this method may not be foolproof since email services frequently update their interfaces. While the enterprise policy approach demands more initial effort, it offers more consistent protection across managed devices.