cloudflare-email-mailchannels/dist/index.js

Send emails via Mailchannels on Cloudflare Workers.

// src/mailchannels.ts
import debug from "debug";
import { Mailbox } from "mimetext/browser";
var _dryrun = false;
function set_default_dryrun(dryrun) {
  _dryrun = dryrun;
}
async function mailchannels(message, dry = _dryrun) {
  const log = debug("mailchannels");
  let recipients = message.getRecipients();
  if (!recipients) {
    throw new Error("No recipients found.");
  }
  if (!Array.isArray(recipients)) {
    recipients = [recipients];
  }
  const sender = message.getSender();
  if (!sender) {
    throw new Error("No sender found.");
  }
  const personalizations = recipients.map((box) => {
    if (box.addr.includes("@mailchannels.net")) {
      log(`Skipping MailChannels address "${box.addr}" to prevent feedback loop.`);
      return null;
    }
    if (box.type === "To") {
      return { to: [{ email: box.addr, name: box.name }] };
    } else if (box.type === "Cc") {
      return { cc: [{ email: box.addr, name: box.name }] };
    } else if (box.type === "Bcc") {
      return { bcc: [{ email: box.addr, name: box.name }] };
    }
    return null;
  }).filter((it) => it !== null);
  if (personalizations.length === 0) {
    throw new Error("No recipients found.");
  }
  const content = [];
  const text = message.getMessageByType("text/plain");
  if (text) {
    log("Found plain text message");
    content.push({ type: "text/plain", value: text.data });
  }
  const html = message.getMessageByType("text/html");
  if (html) {
    log("Found HTML message");
    content.push({ type: "text/html", value: html.data });
  }
  for (const attachment of message.getAttachments()) {
    const type = attachment.getHeader("Content-Type");
    if (typeof type !== "string") {
      continue;
    }
    log(`Found attachment with type "${type}"`, attachment.data.length);
    content.push({ type, value: attachment.data });
  }
  const reserved = [
    "received",
    "dkim-signature",
    "content-type",
    "content-transfer-encoding",
    "to",
    "from",
    "subject",
    "reply-to",
    "cc",
    "bcc"
  ];
  const headers = message.headers.fields.reduce(
    (acc, field) => {
      if (typeof field.name === "string" && typeof field.value === "string") {
        if (reserved.includes(field.name.toLowerCase())) {
          return acc;
        }
        acc[field.name] = field.value;
      }
      return acc;
    },
    {}
  );
  const from = {
    email: sender.addr,
    name: sender.name
  };
  const reply_to_raw = message.headers.get("Reply-To");
  const reply_to = [];
  if (typeof reply_to_raw === "string")
    reply_to.push({ email: reply_to_raw });
  else if (reply_to_raw instanceof Mailbox)
    reply_to.push({ name: reply_to_raw.name, email: reply_to_raw.addr });
  else if (reply_to_raw instanceof Array)
    reply_to_raw.forEach((reply) => {
      reply_to.push({ name: reply.name, email: reply.addr });
    });
  const payload = {
    personalizations,
    from,
    headers,
    subject: message.getSubject() || "",
    content,
    reply_to
  };
  log(personalizations, from, headers);
  const req = new Request(
    "https://api.mailchannels.net/tx/v1/send" + (dry ? "?dry-run=true" : ""),
    {
      method: "POST",
      headers: {
        "content-type": "application/json"
      },
      body: JSON.stringify(payload)
    }
  );
  const res = await fetch(req);
  if (!res.ok) {
    throw new Error(`Failed to send email: ${res.status} ${await res.text()}`);
  }
  log("Email sent successfully.");
  log(await res.text());
}
export {
  mailchannels,
  set_default_dryrun
};