For the most part I don’t want Thunderbird to automatically extract all attachments, but I also receive about 15 automated e-mails every day that have large attachments where I’d like to automatically extract the attachments to a directory.
Attachment Extractor is an extension for Thunderbird that does just that. Simply select the messages that you want the attachments extracted from, right click and select the “Extract Selected Attachments” and the extension takes care of the rest.