There are two ways to delete contacts from SendHub
From the contact's information screen. When you are editing an individual contact's info, you can delete the contact from SendHub by pressing the red "Delete" button in the upper right corner of the screen.
From the Contact List. Click the checkbox next to the contacts you want to delete, then click the "Delete" button above the list.
A confirmation dialogue will appear to confirm that this is what you want to do.
NOTE: Once you've clicked the confirm button, there is no undo.