These are a ready make selection of some of the most popular buttons from the Custom Toolbar Button Maker

Thunderbird, Postbox

about:about

List and open any of the about pages

Lists all the "about" pages so that they can be opened.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

about:config

Open about:config to change settings

Open about:config to change hidden settings that cannot be edited from the Options window.

All Mozilla based programs have settings that can not be changed in the options window. These hidden settings are all reveled in the about:config where anything can be changed or reset.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Empty Trash

Empty The Trash Folder

Empty the Trash Folder

Compatibility: Thunderbird, Postbox SeaMonkey

Toggle Toolbar

Toggle the Main Toolbar

Toggle the main toolbar from showing to hidden. Don't place it on the main toolbar, it is disabled then and will not work.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Not Junk

Mark the selected messages as not junk

Mark the selected messages as Not Junk.

Compatibility: Thunderbird, Postbox SeaMonkey

Select All

Select All Text

Select all the text in the current text box, web page, etc.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Print Preview

Open Print Preview

Open the Print Preview to view a page before printing it.

Paper costs money (and trees) so it is worth checking what the page looks like before you print it. Though it has always amazed me just how much the button gets downloaded.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Add-ons

Open Add-ons Manager

Opens the Add-ons window to perform tasks on your installed Extensions, Themes, Plug-ins and Language packs.

The Add-on's window allows the installation and management of all your extensions and themes. If you need an update, change a setting, swap themes or enable/disable an add-on the Add-ons' window is the place to go. Being able to access this quickly is a necessity for anyone that uses even a handful of add-ons.

The button also contains a drop down menu that allows you to install add-ons, open the add-ons window to the extension or themes tab, or set which websites can install addons.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Customize Toolbar

Customize toolbar, add or remove buttons etc.

Open the customize toolbar window to add or remove items from your toolbar.

The customize Toolbar window is where every button from this extension and others like it get placed for you to then move to your toolbar. Creating the perfect set up is always a moving target that is never quite achieved, but this will make it a little quicker to get there.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Return Receipt

Toggle Return Receipt on/off

Toggle the sending of a return receipt on and off.

Compatibility: Thunderbird, Postbox SeaMonkey