You could create a filter in Thunderbird to delete everything from hotmail.com. However, that would also delete messages from legitimate hotmail.com senders. Fighting spam with static filters is futile. It is therefore recommended to use the TB built-in spam controls. https://support.mozilla.org/kb/thunderbird-and-junk-spam-messages Also, check what spam protection capabilities your email provider offers. Using filters on your email providers server could prevent spam messages to even reach your computer. Depending on your account type you may need to check for false positives on the server though.