When I delete an e-mail, it no longer goes in the trash bin
My trash bin is always empty after I delete an e-mail
Alle antwurden (3)
Go to your account settings (Tools -> Account Settings) Under Server Settings you can configure what should happen when you delete a message (at least for IMAP accounts): Move it to a folder, Mark it as deleted or remove it immediately. You can configure Thunderbird there to move the message to your Trash folder and optionally to empty your trash on exit...
Sorry, I don't even know how to get to the tools-acct. settings
On top of Thunderbird is a menu. It might be hidden, but then if you press the Alt-key or F10 it should be shown. There you can choose Tools -> Account Settings.