# Connect your app
Source: https://docs.infraista.com/en/email/mailgate/connect-your-app



Your app sends through MailGate like through any SMTP server. The service's **Overview** shows the exact
settings under **SMTP settings**.

<Shot name="email/mailgate/smtp-settings" alt="The SMTP settings card: host, port 587 with STARTTLS or 465 with TLS, authentication and limits" />

| Setting            | Value                                                                       |
| ------------------ | --------------------------------------------------------------------------- |
| **Host**           | As shown under **SMTP settings**                                            |
| **Port**           | **587** with **STARTTLS** (recommended), or **465** with &#x2A;*TLS (SSL)** |
| **Authentication** | The username and password of an SMTP login of this service                  |
| **From**           | Any address at one of the service's verified domains                        |

## Send a test email [#send-a-test-email]

Select **Send a test email** on the service, pick a **From** address and a **To** address you can check,
and select **Send test**. It goes through MailGate exactly like mail from your apps (domain check, DKIM
signing, delivery) and appears in **Logs**.

## If something goes wrong [#if-something-goes-wrong]

* **Mail is refused for the From address.** The From domain isn't verified for this service, or the
  login is limited to other domains.
* **Authentication fails.** Check the username and password; after **New password**, the old one stops
  working.
* **Sending is paused.** MailGate refuses mail from the service; contact support to resume it.

## Related [#related]

* [Logs and bounces](/en/email/mailgate/logs-and-bounces)