The following should only be done if you are comfortable changing your Firefox browser configuration.
Due to the latest update of Firefox (v96) it is preventing the email from loading. We hope a future release of Firefox will resolve this issue but the following TEMPORARY FIX should get you back into your emails.
When clicking on Go to Email Account, Firefox keeps returning back to this page. The following steps will resolve this.
Open Firefox and in the URL type "about:config", press Enter and click 'Accept the risk and continue'
In the search box type 'network.cookie.samesite.schemeful'
Double-click on 'true' to turn it to 'false'
When it's turned to false it will become bold.
You should now be able to access your Inbox.com email