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

Thunderbird, Postbox

Undo

Undo Last Change

Undo last change/action.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Toggle Proxy

Toggle The Proxy On & Off

Toggles the Proxy between on and off for quick changing of networks.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Options Menu

Show Options Menu

Show the options menu in the compose mail window.

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

Save Attachments

Save All Attachments From Message

Save Attachments from an message.

Compatibility: Thunderbird, Postbox SeaMonkey

Format

Show the Format Menu

Show the Format Menu

Compatibility: Thunderbird, Postbox SeaMonkey

Free Memory

Free Unused Memory

Free unused memory that Firefox is currently using.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Options

Open options

Opens the Options window so you can change settings easily.

Firefox, Thunderbird and Sunbird all have a huge number of settings. Often you will find a need to change one. About to visit your banking site, so you want pop ups enabled, or what ever your current need might be. The button brings the option window to you quicker.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Run Application

Run an external application

Runs an external application

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Switch Profile...

Change Profile that you are currently using.

Switch the Profile that you are currently using.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey