If you re-schedule your send then edit the subject line of the message, this change won't be reflected in the scheduled send. You will need to cancel the scheduled send and start again to have the subject line changed. This is also true for other sender details, such as the from name and from address.
- Select Reports from the sidebar.
- Click the Current Sends tab. Any scheduled sends will now appear.
- Click next to the scheduled send you wish to cancel.
- Select Reschedule from the dropdown menu.
- Confirm the action. You will then be taken back to the message send screen to select your recipients and schedule your send once more.