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

Thunderbird, Postbox

Forward As Attachment

Forward message as an attachment

Forward the current message as an attachment.

Compatibility: Thunderbird, Postbox SeaMonkey

Insert

Show Insert Menu

Show Insert Menu

Compatibility: Thunderbird, Postbox SeaMonkey

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

Threads with Unread

View Threads With Unread

View only the threads in the current folder that have unread messages.

Compatibility: Thunderbird, Postbox SeaMonkey

Unread Threads

View Unread Threads

View threads that you have not read yet.

Compatibility: Thunderbird, Postbox SeaMonkey

Watched Threads with Unread

View Watched Threads With Unread

View watched threads that have unread messages in them.

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

Add Email

Copy Email Address to Address Book

Add a new email address to the address book.

Compatibility: Thunderbird, Postbox SeaMonkey

Archive Thread

Send the Selected Thread to the Archive

Send the Selected Thread to the Archive

Compatibility: Thunderbird, Postbox SeaMonkey

Codefisher

Open Codefisher.org

Opens various pages of the Codefisher.org website.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey