Дополнения

Mark All Read Button от Mark S Baines

Adds toolbar buttons to Mark All emails as Read, Mark Thread as Read, and Goto Next Unread Thread.

Phoenity Buttons от Dillinger

Adds some toolbar buttons using phoenity icons.

Exit Button Thunderbird от Mark S Baines

Adds a toolbar button to exit Thunderbird. Go to View menu, Toolbars, Customize... and drag the icon where you want...

Disable "You" от JasnaPaka

Addresses in the From/To/Cc headings are since Thunderbird 3 replaced with word "You" if they match any of your identities. This extension disables this function.

Toggle Headers от mattsch

Allows to switch between the normal header view and viewing all headers when viewing a message by using a keyboard shortcut (Ctrl+H).

Airmail от taeco