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

Thunderbird, Postbox

Send Without Save

Send message without saving a copy

Send message with out saving a copy to the sent folder. If you want this as the permanent behaviour, there is an option in account settings under 'Copies & Folders'

Compatibility: Thunderbird, Postbox SeaMonkey

Account Setup

Run wizard to setup a new account

Run Account Wizard to set up a new account in Thunderbird.

Compatibility: Thunderbird, Postbox SeaMonkey

Detach Attachments

Detach All Attachments From Message

Detach Attachments from an email.

Compatibility: Thunderbird, Postbox SeaMonkey

Go

Show the Go Menu

Show the Go Menu

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

Archive Thread

Send the Selected Thread to the Archive

Send the Selected Thread to the Archive

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

Download/Sync Now…

Run download and sync before going offline

Runs the download and sync now tool, so that messages can be used when you go offline.

Compatibility: Thunderbird, Postbox SeaMonkey

Forward As Attachment

Forward message as an attachment

Forward the current message as an attachment.

Compatibility: Thunderbird, Postbox SeaMonkey