You can cancel a marketing email you've scheduled to send in the future, or aSmart Send email that is still processing. You can also cancel a batch marketing email that's still processing for a larger contact list.
Cancel a sent or scheduled email
In your HubSpot account, navigate to Marketing > Email.
Locate the email you've sent, and click the name of the email to open the performance page.
At the top of this page, click the Actions dropdown menu and select Cancel processing or Cancel scheduled email.
In the dialog box, click Cancel processingor Cancel scheduled email to confirm you want to cancel this email.