You can opt out of an individual poll by clicking on the “opt out” link in any email from BallotBox that asks you to participate in that poll.
If you want an organization to stop including you in any of its voter lists for future polls, you will need to contact that organization with your request. The contact email address for each organization appears in each email from BallotBox that invites you to vote in a poll to make it easy for you to contact them.