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

Thunderbird, Postbox

Options Menu

Show Options Menu

Show the options menu in the compose mail window.

Compatibility: Thunderbird, Postbox SeaMonkey

Plain Text Paste

Paste Text With No Formatting

Paste text into Thunderbird without any formatting.

Compatibility: Thunderbird, Postbox SeaMonkey

Reply to Sender Only

Reply only to the sender of the email

Reply only to the sender of the email.

Compatibility: Thunderbird, Postbox SeaMonkey

Rewrap

Rewrap

Rewraps the message text

Compatibility: Thunderbird, Postbox SeaMonkey

Tasks In View

Toggle Tasks in View

Toggle the Task in View panel in Sunbird.

Compatibility: Thunderbird, Postbox SeaMonkey

Toggle Starred

Toggle Starred Status

Toggle the starred status (look for the star next to the message).

Compatibility: Thunderbird, Postbox SeaMonkey

Toggle Tasks

Toggle the task bar

Toggle the task bar between visible and hidden.

Compatibility: Thunderbird, Postbox SeaMonkey