It appears that Tools / Message Filters only work on incoming messages. Once the message is in the Inbox folder (or any other folder for that matter) then Message Filters play no further part. I get specific messages with offers valid for, say, 14 days. Eventually the messages become outdated and I have to remove them by hand. I want Thunderbird to look into the Inbox folder and run a Message Filter to clean out the specific messages that are older than 14 days and to do this each time I look for new mail from the server.
I am not talking about incoming messages that are outdated by 14 days. I am talking about specific messages that have arrived and have been sitting in the Inbox folder for more than 14 days.
Thank you kindly