i just got my behold 2 & was so frustrated about not being able to delete all my unwanted emails all at once...what a terrible feature not to have. but i found the solution...just go to market & download the "K9" application & it's done. you can select all emails, then delete AND they don't go to a "junk" folder...they are gone for good. maybe everyone knows about K9 already but i just had to share this wonderful information for anyone encountering this!!
