Welcome to the forum! There are a lot of great people here willing to lend a hand anytime. Often using the search feature (in the toolbar at the top of every page) will lead you to the answers you're looking for. If not, feel free to post a question in the appropriate area.
Please take a moment to view the information linked below my signature to get the most out of your iPad as well as our forum.
With respect to your question, you probably need to change the Mail settings for the account.
On your iPad open the Settings App. Tap on "Mail, Contacts Calendars". From there tap on the mail account in question, then:
Account > Advanced (scroll down or clear the keyboard to see it) > Deleted Mailbox > On the Server > Trash (not Trash under "On My iPad")
See if that doesn't take care of it!
I've moved your post to the iPad Help area where you're likely to get a better response to your question and help those that follow.
Welcome again and enjoy!
BTW, we used to live in Tauranga as well as Auckland...miss it a lot and really wish we were there for the Rugby World Cup. Go The All Blacks!