re :''my inbox only shows unread messages. '' This sounds like you have filter operating on the Inbox folder. Select that 'Inbox' folder. On the right where you see the list of emails, just above it will be the 'Quick Filter Bar' Check to see if one or more of those icons is highlighted. There is an icon called 'Unread' which has a tooltip 'Show only unread messages' If it is enabled/highlighted, click on that icon to disable it. The 'Pin' icon may also be highlighted which means you selected a filter on another folder and then selected to pin that filter to all folders, If it is highlighted click on it to disable it. Info on Quick Filter Bar: https://support.mozilla.org/en-US/kb/quick-filter-toolbar It is not displaying the latest version, but generally the info is still the same. I've added an image below, showing what it looks like in version 78 as some icons changed.