Empty the Trash

There is no single "empty the trash" button in the current version of Unibox. Empty the Trash by performing the following steps:

Empty the Trash

Firstly, switch to the Trash group by using the group drop-down at the very top left of Unibox.

Empty the Trash

Secondly, select all contacts from the Contact menu

Empty the Trash

Thirdly, delete all messages by using the Contact menu again.

The above steps works pretty much the same for Junk messages. (Just select the Junk instead of the Trash group)