Outlook365 Provider

The Outlook365 provider sends emails through the Microsoft Graph sendMail endpoint.

Runtime Support: Universal (Node.js, Deno, Bun, Cloudflare Workers) — uses the Fetch API.

Authentication is delegated: you supply a static accessToken or an async getAccessToken (e.g. backed by @azure/msal-node). The provider never bundles an auth SDK, so it stays dependency-light and runtime-agnostic.

Setup

import { createMail } from "@visulima/email";
import { outlook365Provider } from "@visulima/email/providers/outlook365";

const mail = createMail(
    outlook365Provider({
        // Bring your own OAuth2 token with the `Mail.Send` scope.
        getAccessToken: async () => getGraphAccessToken(),
        userId: "sender@contoso.com", // or "me" (default) to use the token's own mailbox
    }),
);

Configuration

The Outlook365Config interface extends BaseConfig. One of accessToken / getAccessToken is required.

Basic Usage

const result = await mail.send({
    from: { email: "sender@contoso.com" },
    to: { email: "user@example.com" },
    subject: "Hello from Outlook365",
    html: "<h1>Welcome!</h1>",
});

Note: Microsoft Graph always sends as the authenticated user / userId, so the from address is effectively the mailbox the token is scoped to. Graph's sendMail returns 202 Accepted with an empty body, so a message id is synthesised in the result.

Provider-Specific Email Options

The Outlook365EmailOptions interface extends EmailOptions with:

Supported Features

• ✅ Attachments
• ✅ Custom headers
• ✅ HTML & text bodies
• ✅ Reply-To
• ❌ Batch sending
• ❌ Tagging / templates / tracking (use Graph directly for those)