How do I empty all the emails in the Trash folder?

Mobile:

1. Open the Trash folder. Tap your account avatar at the top-left of the message list to open the folder drawer, then tap Trash — see how to access other folders.
2. In the top bar, tap the trash-can icon. Three icons sit on the right of the top bar: the trash can is the first of them, to the left of the speech-bubble icon and the ⋯ menu. The ⋯ menu is the one in the corner, not the trash can.
3. In the Delete All dialog — "You are about to permanently delete all messages from Trash folder. Are you sure?" — tap OK.

Emptying the Trash deletes those messages permanently. They cannot be recovered from within BlueMail afterwards.

Desktop: In order to empty the Trash folder, please click the Empty Trash button at the bottom of your mail list.