If you mean the icons on the Mail Toolbar, right-click the bar, Customize... and choose Text in the Show menu.

Thanks! That solved part of my irritation.

But I really want to know how to get rid of the icons beside: Inbox Drafts Sent Etc.

I feel like Thunderbird thinks I don't know how to read.

Add this code to a userChrome.css file:

/* Folder pane icons */
#folderTree treechildren::-moz-tree-image {
list-style-image: none !important; }

/* Reduce vertical alignment display width */
#folderTree treechildren::-moz-tree-indentation {
width: 1px !important;
}

See attached picture.

Help/Troubleshooting, Profile Folder, Open Folder, close TB, create a new folder named chrome, create a new document in chrome with a text editor, name it userChrome.css, Save as type: All files *.*, copy in the above code, change the numbers as desired. Double-click toolkit.legacyUserProfileCustomizations.stylesheets to true in Options/General/Config. editor, restart TB.

Thanks for your reply, but that was waaaay over my head. I don't use Chrome for anything, so I'm pretty sure I don't have a userChrome.css file.

I was really hoping for a hidden button in Options or in Tools.

Am I out of luck? Could I put in a request somewhere?

This has nothing to do with the Chrome browser. You have to create a chrome folder and a userChrome.css file, according to the instructions.

I don't think there's anywhere to make a request, as the css method has been the standard approach since TB and Firefox were first released.

I am still waiting for the customization button option to get rid of the useless and annoying icons too. If it can be done for one tool bar, why not the entire layout? I do not understand why this change was made without an option to avoid it or repair the damage. It has meant that my email expansion now occupies more than one page, requiring scrolling, solely due to the icons. The spacing in email lists is also a problem that I need a solution to. I am not comfortable making registry entries.

Spacing in the Folders and Threads panes can be adjusted with another css entry:

https://support.mozilla.org/en-US/questions/1310152