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

Thunderbird, Postbox

Update

Check For Updates

Check for updates to the currently open application.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Zoom Out

Reduce Text Size

Reduce the text size so it is not so big.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

About

About

Open the about window. Useful for checking exactly what version you have installed.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Empty Trash

Empty The Trash Folder

Empty the Trash Folder

Compatibility: Thunderbird, Postbox SeaMonkey

Status Bar

Toggle The Status Bar

Toggle the status bar from hidden to shown. Hide it to get the most out of your screen space, and show it when it really needed.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Cookie Manager

Opens the cookie manager for the current web page.

Opens the cookie manager for the current web page. On middle click opens in a new tab.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Redo

Redo Last Change

Redo the late change.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

about:plugins

Open about:plugins to view installed plugins

Open about:plugins to view installed plug-ins.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Cookie Exceptions

Open the Cookie Exceptions dialog

Open the cookie exceptions dialog.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Get Extensions

Get more Thunderbird extensions

Open addons.mozilla.org on the page to get more Thunderbird extensions. Link can be change using about:config if you prefer another site.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey