my brother is forwarding to me all his email without my consent

If you have you brothers email address set up as a mail account in Thunderbird, then the emails are not being forwarded; they are just being downloaded. Maybe your brother visited you and created a mail account for his email address so he could read emails. If that is the case then you should see his email address/account name in the Folder Pane as a separate account to you. You will be able to see the mail account for his email address in 'Account Settings'. * Access Account Settings: * To remove it - in left pane select the account name * click on 'Account Actions' * click on 'Remove Account' If you are receiving emails sent to your brother and they are downloading into your email address mail account then it's likely he has logged on to his webmail account and set up to auto forward all emails to your email address. In this case, the 'TO' will have his email address instead of yours and the Subject will look normal - it will not have a 'Fwd' at the begining. I have set this up so all emails sent to my elderly mother send a copy to me as well. The emails really look like they are not forwarded - they just arrive in my Inbox. Ask your brother to logon to his webmail account via a browser and check to see if he has set up auto forwarding to your email address and if yes, remove it. If you are getting a load of emails which say 'FROM' your brother and TO your email address and the subject has a FWD at the start, then he is forwarding emails. Maybe he has set this up in an email client like Thunderbird or in webmail using a Message Filter to forward everything to your email address. So...check to see if your brother has managed to set up a mail account in your Thunderbird. Otherwise, the bottom line is this....it's not a Thunderbird problem. Talk to your brother because he may not be aware of it.