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

Thunderbird, Postbox

Update

Check For Updates

Check for updates to the currently open application.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

View Menu

Show the view menu

Show the view menu.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey

Add Email

Copy Email Address to Address Book

Add a new email address to the address book.

Compatibility: Thunderbird, Postbox SeaMonkey

All Threads

View All Threads

View all the threads in the current folder, not just unread or some other sub set.

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

Detach Attachments

Detach All Attachments From Message

Detach Attachments from an email.

Compatibility: Thunderbird, Postbox SeaMonkey

Edit Draft

Edit Saved Draft or Message

Edit a message that you have saved as a draft.

Compatibility: Thunderbird, Postbox SeaMonkey

Edit Menu

Show the edit menu

Show the edit menu.

Compatibility: Pale Moon Thunderbird, Postbox SeaMonkey