I have used Thunderbird for several years with no problems. Recently, even with the setting to not delete emails automatically after 30 days, the emails disappear after 30 days, including from the inbox, sent and archives. It deleted archived messages for the last 3 years. I did not change any settings, the program just did this suddenly. Today, it just deleted all of the messages in the inbox from the past 25 days and installed the latest update. How can I get this to work correctly?