If you need to halt an active email campaign before it finishes sending, you can stop it from the Campaigns section. This will prevent any remaining scheduled emails from going out to recipients who haven't received them yet.
How to stop a campaign:
Click Campaigns in the left navigation menu.
Find the campaign you want to stop — use the search bar or scroll to locate it.
Click the Stop button next to the campaign name.
Confirm when prompted.
The campaign will stop immediately. Emails already sent will remain in recipients' inboxes — stopping a campaign doesn't unsend anything.