We are a small nonprofit with a very small team. We are considering different options for email marketing programs and a comprehensive lead tracking system. We currently use Mailchimp for newsletters but are looking for a robust and integrated system with email nurture sequences and the ability to better track folks throughout their communication and engagement with us. We are looking at tools like ConvertKit, HubSpot, ActiveCampaign etc, but need an affordable and user friendly tool and don't know how to choose. We would love a volunteer who really understands the pros and cons of these products and can help advice on selection (and perhaps, later, implementation). Thanks!