Can I add prospects to an existing list?

When you add prospects to Email Sequences via CSV or manual input, that import of prospects becomes a unique list. You can add additional prospects directly to a campaign instead of needing to add them to a list first.

If you imported a list to a campaign but you were missing a few prospects, simply add those prospects to the campaign.

What about ongoing syncs with CRMs?

If you set up an ongoing sync with a CRM, prospects will automatically be added to the same list since it's related to an ongoing sync.