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 the current message as an attachment.

Install Forward As Attachment

Download Forward As Attachment

Compatibility: Thunderbird, Postbox SeaMonkey

Insert

Show Insert Menu

Install Insert

Download Insert

Compatibility: Thunderbird, Postbox SeaMonkey

Send Without Save

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'

Install Send Without Save

Download Send Without Save

Compatibility: Thunderbird, Postbox SeaMonkey

Threads with Unread

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

Install Threads with Unread

Download Threads with Unread

Compatibility: Thunderbird, Postbox SeaMonkey

Unread Threads

View threads that you have not read yet.

Install Unread Threads

Download Unread Threads

Compatibility: Thunderbird, Postbox SeaMonkey

Watched Threads with Unread

View watched threads that have unread messages in them.

Install Watched Threads with Unread

Download Watched Threads with Unread

Compatibility: Thunderbird, Postbox SeaMonkey

Account Setup

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

Install Account Setup

Download Account Setup

Compatibility: Thunderbird, Postbox SeaMonkey

Add Email

Add a new email address to the address book.

Install Add Email

Download Add Email

Compatibility: Thunderbird, Postbox SeaMonkey

Archive Thread

Send the Selected Thread to the Archive

Install Archive Thread

Download Archive Thread

Compatibility: Thunderbird, Postbox SeaMonkey

Codefisher

Opens various pages of the Codefisher.org website.

Install Codefisher

Download Codefisher

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey