Click on the junk column to sort on that column. This will place all those messages together. Click on the first junk message. Move to the last junk message and hold the shift key while clicking it. They should all be selected now. Press the delete key. You can set junk controls to send junk messages to their own folder. Here is the article on junk controls. http://kb.mozillazine.org/Junk_Mail_Controls Read receipt is under Options in the Write window. Yes the recipient will know. They have the option to ignore the request. Read receipts are not an exact science. You may or may not get one if you request it. Goggle it to learn more.