I wish to delete all emails from vouchercloud

You can either check each email you wish to delete and click delete once or check the delete all box to the left of the toolbar and then click on delete.

select inbox click on the email you wish to delete ,click the delete tab.if you want to delete all highlite all emails and click on delete tab,if you delete an email by mistake you can look in your deleted folder and select the email you wish to keep and then go to the move tab click on the drop down tab and select where you wish to save the email to you can also do this same operation to retrieve all your emails

Left click and hold, while holding drag the pointer down you email list, this will high light them in blue. Release the button when you get to were you wish to stop.
Check that all the high lighted emails are what you wish to delete. When you are happy wit the selected emails, left click on the delete or trash icon.

If you are referring to Outlook.com then you go to it's settings and simply delete the old account and add a new account. If you are referring to MS outlook then you there are quite a few steps to do that.

You can select emails by pressing and holding Ctrl key and the delete them.

Tick in the box at the start of the emails you wish to delete
scroll to the furthest you want to delete hold the shift key place a tick in that box all emails will be selected in between select Delete all emails selected will be deleted.

Tick in the box at the start of the emails you wish to delete
scroll to the furthest you want to delete hold the shift key place a tick in that box all emails will be selected in between select Delete all emails selected will be deleted

Tick in the box at the start of the emails you wish to delete
select Delete all emails selected will be deleted

Tick in the box at the start of the emails you wish to delete
scroll to the furthest you want to delete hold the shift key place a tick in that box all emails will be selected in between select Delete all emails selected will be deleted.

Hope this helps.