After adding your recipients please go to the button SEND.
You can either choose to send your "Invitation", "Save the date" or "Card" manually by clicking on these options, or you can SCHEDULE your sending on a later date at a specific time.
You can also select your recipients first and then go to SEND if you only wish to send a selected few.
You can also filter your list by using "tags" or by the status of the recipient, e.g. "not sent" or "viewed" and then go to SEND to send only to this filtered list.