how do i delete multiple emails at once

Click on the first message you want to delete and and then move to the last message you want to delete and press shift and click, this will highlight all the messages you want to delete and then press delete! Hey presto!

Place the cursor on and click on one message in the list of messages to select it, then use shift-click to select a range of messages, or then use control-click on other messages to select specific (and isolated) messages, then ⌘ Delete

If you haven't seen this Apple material already, the Mac 101 pages can help you get more out of OS X.

@mamandelagrace: This question has been answered and needs to be marked as such. These wonderful people do like to get their points plus it clears the list of unanswered questions. I don't know about Windows 7, but this has been the standard on all computers on which I have worked so long that I am unable to remember when it was not.

Just to correct a little typo - it's command-click, no control-click to select multiple isolated messages.

On an ipad?

FYI - with Windows 7 on a PC this doesn't work. The most basic task I have to do one at a time. Very frustrating.