Email Verification for Nonprofit Donor & Supporter Lists

const MAILBEAM_KEY = process.env.MAILBEAM_KEY!;

interface Supporter { id: string; email: string; lastGift?: string }

async function verifyBatch(emails: string[]) {
  const res = await fetch("https://api.mailbeam.dev/v1/verify/batch", {
    method: "POST",
    headers: {
      "Authorization": `Bearer ${MAILBEAM_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ emails }),
  });
  const { results } = await res.json();
  return results as Array<{
    email: string;
    valid: boolean;
    score: number;
    status: "deliverable" | "risky" | "undeliverable" | "unknown";
  }>;
}

// Clean a legacy donor file before the year-end appeal
export async function cleanDonorList(supporters: Supporter[]) {
  const results = await verifyBatch(supporters.map((s) => s.email));
  const byEmail = new Map(results.map((r) => [r.email, r]));

  const mailable: Supporter[] = [];
  const suppress: Supporter[] = [];

  for (const supporter of supporters) {
    const r = byEmail.get(supporter.email);
    // Suppress undeliverable + low-confidence so the appeal
    // doesn't damage the sender domain loyal donors rely on.
    if (r && r.valid && r.score >= 50) {
      mailable.push(supporter);
    } else {
      suppress.push(supporter);
    }
  }

  console.log(`Mailable: ${mailable.length} | Suppressed: ${suppress.length}`);
  return { mailable, suppress };
}