When you intend to cancel scheduled email, you have to enter the email marketing menu first.
There are 2 ways you can do to cancel schedule on email marketing:
Select an email that you want to cancel on email marketing list. Click Email subject that you are referring to. Then click Cancel Schedule button. Afterwards, the question pop-up will show to ensure your decision. Click Back to cancel action, then you will be brought back to email marketing list. Click Cancel Schedule Block to confirm action, then you will be directed to Compose email to the email.
Select an email that you are referring to on email marketing list. Click Button Action Edit. After it, the question pop-up will show to ensure your decision. Click Back to cancel action, then you will be brought back to email marketing list. Click Cancel Schedule Block to confirm action, then you will be directed to Compose email to the email.