---
title: How do I connect a service for sending my app's emails?
question: Postmark SendGrid Mailgun sending domain DNS setup
area: integrations
surface: desktop
audience: beginner
keywords: [transactional email, Postmark account token, SendGrid sender authentication, Mailgun account key, DNS, DKIM, email verification]
related: [integrations-overview, connect-cloudflare, connect-godaddy]
updated: 2026-09-09
visibility: public
---

# How do I connect a service for sending my app's emails?

Connect **Postmark**, **SendGrid** or **Mailgun** in **Settings → Integrations**, then ask your project's agent to help set up the sending domain. These connections prepare email delivery for your app; they are not the separate Email workspace or a personal mailbox login.

## Before you start

You need authority over the sending domain and the email-provider account. Domain verification may require [DNS](../glossary/what-the-words-mean.md) changes. Review those changes before applying them, and do not replace existing mail records without understanding their effect.

Provider billing and sending limits are separate from Codus.

## Connect the correct credential

1. Open **Settings → Integrations** and find your provider.
2. Use the card's setup link:
   - **Postmark** needs an **account token**, not a server-only token, for sending-domain setup.
   - **SendGrid** needs permissions for sender authentication and the account actions being used. A **Mail Send only** key is insufficient for domain setup; do not grant broader permissions than your task needs.
   - **Mailgun** needs an account-level API key, not a domain sending key, to create and verify domains.
3. Paste it into the credential field and click **Connect**.
4. Check the account and region information returned.
5. Tell the project agent the exact sending domain and intended provider. If DNS changes are needed, connect your DNS service or apply the reviewed records through its dashboard.

A saved connection is not a verified domain. DNS and provider verification can remain pending after connection succeeds.

## How do I know it worked?

The provider confirms the domain is verified, and an authorised test email reaches its intended recipient. Check sender details and spam placement before relying on production email.