> ## Documentation Index
> Fetch the complete documentation index at: https://docs.daoco.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Connect a custom SMTP server

> Send approved individual emails through an existing SMTP server with encrypted credentials.

Custom SMTP is an **Available** Mail & Calendar integration for outbound email. It works with SMTP credentials from providers such as Amazon SES, Mailgun, Postmark, Microsoft 365, and ordinary hosted mailboxes.

Custom SMTP sends individual messages. It does not read inboxes, manage mailing lists, process bounces, track opens, or replace a campaign email provider.

## Before you connect

Get these values from the mail provider:

* SMTP hostname
* Port 25, 465, 587, or 2525
* TLS or STARTTLS security mode
* Username
* Password or app password
* Approved sender email

The server must have a public internet address and a valid TLS certificate. daoco blocks private and local network addresses.

## Connect the server

<Steps>
  <Step title="Open Custom SMTP">
    In daoco, open **Connections** → **Integrations** → **Mail & Calendar** and
    choose **Custom SMTP**.
  </Step>

  <Step title="Enter the connection details">
    Enter the server, port, security mode, username, password, and sender email.
    The sender name and reply-to email are optional.
  </Step>

  <Step title="Test and connect">
    Choose **Test and connect**. daoco authenticates with the server and sends a
    test message to the sender address. daoco saves the connection only after
    the test succeeds.
  </Step>

  <Step title="Send from chat">
    Ask [`/integration`](/connections/integrations#what-is-mcp) to send a
    completed email through the Custom SMTP connection. daoco shows the exact
    send for approval before it contacts the server.
  </Step>
</Steps>

<Warning>
  Do not paste SMTP credentials into chat. daoco encrypts credentials entered in
  the connection form. Reconnect the integration after rotating the provider
  password.
</Warning>

## Delivery and compliance

The connected mail provider controls sender authorization, sending limits, and delivery. Configure SPF, DKIM, and DMARC with that provider before sending customer email.

SMTP can leave delivery uncertain if a network timeout happens after the server accepts message data. daoco does not retry a failed SMTP send automatically. Check the provider's sent-mail or delivery logs before requesting another send.

Use an email marketing provider for bulk campaigns, unsubscribe management, suppression lists, bounce handling, and complaint processing.