Summary #

Gmail added an “Advanced Attachment Feature” that uses Flash to attach files.  Currently, both the Chrome and FireFox browsers fail to recognize an authenticated proxy so you may get the following error after trying to attach a file: “Attachment failed. This may be due to a proxy or firewall error“.

More Information #

The best solution is to switch back to Gmail’s “Classic Uploader”.  You can change your attachment preferences by following these instructions:  Click on the gear icon in the upper-right corner of your Gmail account and select Gmail settings > General tab > Scroll to the bottom and select the option: Basic attachment feature > Save Changes.  After you have saved your changes, you will be able to attach files to your Gmail messages.

If you want to use Gmail’s advanced attachment features and you already allow ALL of your users access to Gmail then you can add mail.google.com as an authentication exception in SecureSchool by going to Website Filtering > Authentication Exceptions.

Currently, Internet Explorer 9.x works with Google’s advanced attachment features so no further changes need to be made in Gmail or SecureSchool at this time for IE users.