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

Thunderbird, Postbox

Zoom In

Enlarge Text Size

Enlarge the text size on sites that makes the text so small you can't read it.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Delete Attachments

Delete All Attachments From Message

Delete Attachments from and email.

Compatibility: Thunderbird, Postbox SeaMonkey

Return Receipt

Toggle Return Receipt on/off

Toggle the sending of a return receipt on and off.

Compatibility: Thunderbird, Postbox SeaMonkey

Source

View Page Source

View the page or message source code.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Delete

Delete Selected Text

Delete the currently selected item(s) or text.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Edit as New

Edit Message as New

Edit an email.

Compatibility: Thunderbird, Postbox SeaMonkey

Message

Show the Message Menu

Show the Message Menu

Compatibility: Thunderbird, Postbox SeaMonkey

Message Pane

Toggle Message Pane

Show/Hide the Message Pane.

Compatibility: Thunderbird, Postbox SeaMonkey

Not Junk

Mark the selected messages as not junk

Mark the selected messages as Not Junk.

Compatibility: Thunderbird, Postbox SeaMonkey

Status Bar

Toggle The Status Bar

Toggle the status bar from hidden to shown. Hide it to get the most out of your screen space, and show it when it really needed.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey