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

Thunderbird, Postbox

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

Undo

Undo Last Change

Undo last change/action.

Compatibility: Pale Moon 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

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

Delete Junk

Delete Junk Messages

Empty the junk email folder of all junk email.

Compatibility: Thunderbird, Postbox SeaMonkey

Empty Trash

Empty The Trash Folder

Empty the Trash Folder

Compatibility: 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

Redo

Redo Last Change

Redo the late change.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Zoom Text Only

Toggle between text and page zoom.

Toggle between text and page zoom.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Delete

Delete Selected Text

Delete the currently selected item(s) or text.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey