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

Thunderbird, Postbox

Previous Message

Get Real Previous Message

Get the previous message. Unlink the default Thunderbird buttons this just go to the previous in the list, or if shift is pressed, the previous unread.

Compatibility: Thunderbird, Postbox SeaMonkey

Toggle Read

Toggle Message Read Status

Toggle the Read status of the currently selected message.

Compatibility: Thunderbird, Postbox SeaMonkey

Delete Events

Delete Selected Events

Delete an event.

Compatibility: Thunderbird, Postbox SeaMonkey

Delete Tasks

Delete Selected Tasks

Delete a task.

Compatibility: Thunderbird, Postbox SeaMonkey

Edit Draft

Edit Saved Draft or Message

Edit a message that you have saved as a draft.

Compatibility: Thunderbird, Postbox SeaMonkey

Format

Show the Format Menu

Show the Format Menu

Compatibility: Thunderbird, Postbox SeaMonkey

Go

Show the Go Menu

Show the Go Menu

Compatibility: Thunderbird, Postbox SeaMonkey

New Event

Add a new event to the calendar.

Add a new event into the calendar.

Compatibility: Thunderbird, Postbox SeaMonkey

New Task

Add a new task to the calendar.

Add a new task to the calendar.

Compatibility: Thunderbird, Postbox SeaMonkey

Open in Conversation

Open current message in Conversation

Open the current message in a conversation tab

Compatibility: Thunderbird, Postbox SeaMonkey