Planet Ergo

As most users I have some folders in Thunderbird with a huge number of mails. Now I want that Thunderbird deletes mails automatically. How to make Mozilla Thunderbird delete old messages in a folder automatically?

• Click on the desired folder with the right mouse button.
• Select the Properties... entry from the menu.
• Switch to the Retention Policy tab.
  
• Uncheck Use my account settings
• Delete all but the last __ messages or Delete messages more than __ days old