re :''I did set the filter to delete any message with this in the body. I know its spam but I dont even want thunderbird to take it from the server''. You mention 'Junk' folder so I'm presuming you are talking about a POP mail account. POP mail accounts can only access the server Inbox and download whatever is in that folder. If you have set up a filter in the webmail account via a browser then it is possible to filter that email out of the 'Inbox' into 'Spam' folder, so Thunderbird cannot download it. Then set webmail 'Spam' to auto empty periodically. re: Message Filter in Thunderbird Is it running when 'getting new mail' AND 'Filter '''after''' Junk Classification' Generally, you train Thunderbird to recognise junk/spam mail and it all goes into 'Junk' folder if pop or 'Spam' if imap. Then you can scan the 'Junk' folder in case a good email goes to the wrong folder and then right click on folder and select 'Empty Junk'. You can also set up your Account Settings for mail account > Junk Settings, to automatically delete anything older than x days from Junk. So if your Message Filter is not deleting and email ends up in Junk folder then you need to adjust the Message Filter to scan '''before''' junk classification.