Perhaps, perhaps not.

If you are using an IMAP account, the retention of mail in Thunderbird's version of your account is directly syncronised to the server version and the server is considered canonical. This means that what happen into your account on the server is reflected in the Thunderbird version. If you provider has a strict policy around retention of mail (7, 14, 30 days, a year or whatever. This policy will be applied to Thunderbird.

IF this is the case you can move mails to the "Local folders" part of Thunderbird. This moves the mail from "The Cloud" to a dedicated local store on your machine. It also makes you responsible for backing it up in case your system crashes. There are on copies anywhere else.

So you could move your mails from the accounts trash to the local folders. But it will not prevent another lot going there in a month or a year or whenever the provider runs their house keeping to clean up mail that has "expired" So you may need to reconsider how you do mail, moving stared message to local folders when you star them.

Thank you Matt, but I am on " Pop3.mail.wowway.com" My messaages are saved until I delete them. I have no idea how this all happened.

dee hausch