Lifecycle emails, also known as drip email marketing, involve sending a series of automated emails to prospects and customers over time based on their behaviors and stage in the buying cycle. The emails are meant to nurture prospects by providing relevant content, building trust and relationships, addressing concerns, and ultimately moving them closer to becoming sales-ready leads. Effective lifecycle email programs segment audiences, map the buying cycle, develop content to align with each stage, automate email delivery, track engagement metrics, and integrate with CRM to handoff qualified leads to sales. Continuous testing and optimization of content, timing, and messaging is important to maximize results like conversion rates and revenue.