You’ll find a link to your archived campaigns by clicking on Campaigns:
Clicking this link will open a new window to your Archive Page, which gets indexed by Google:
To delete a listing from your Archive Page, you’ll have to delete the campaign from your Campaign Dashboard. Keep in mind that this will also delete any Reporting data for that campaign, too. Export that data first if you want to have access to it.
No problem! You can choose whether or not to archive any campaign you send by checking or un-checking the Archive Campaign feature on the Campaign Settings page of the Campaign Builder: