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

Thunderbird, Postbox

New Event

Add a new event into the calendar.

Install New Event

Download New Event

Compatibility: Thunderbird, Postbox SeaMonkey

New Task

Add a new task to the calendar.

Install New Task

Download New Task

Compatibility: Thunderbird, Postbox SeaMonkey

Next Message

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

Install Next Message

Download Next Message

Compatibility: Thunderbird, Postbox SeaMonkey

Not Junk

Mark the selected messages as Not Junk.

Install Not Junk

Download Not Junk

Compatibility: Thunderbird, Postbox SeaMonkey

Paste As Quotation

Paste text so that it appears as a quoted message.

Install Paste As Quotation

Download Paste As Quotation

Compatibility: Thunderbird, Postbox SeaMonkey

Plain Text Paste

Paste text into Thunderbird without any formatting.

Install Plain Text Paste

Download Plain Text Paste

Compatibility: Thunderbird, Postbox SeaMonkey

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.

Install Previous Message

Download Previous Message

Compatibility: Thunderbird, Postbox SeaMonkey

Read

Open the currently selected message in Thunderbird.

Install Read

Download Read

Compatibility: Thunderbird, Postbox SeaMonkey

Remote Content

Opens the window to set exceptions for the loading of remote content

Install Remote Content

Download Remote Content

Compatibility: Thunderbird, Postbox SeaMonkey

Reply to Sender Only

Reply only to the sender of the email.

Install Reply to Sender Only

Download Reply to Sender Only

Compatibility: Thunderbird, Postbox SeaMonkey