# How to use Velocity MTA as an SMTP Relay

All email sent through the ESP platform must originate with a Customer Account, including mail sent using Velocity MTA. 

You can't connect to the MTA directly and use SMTP Relay while going outside of the ESP platform. 

To use SMTP Relay with Velocity MTA, you must add the MTA to a Postal Route, give a Customer Account access to that Postal Route, and then use SMTP Relay through that Customer Account. 

SMTP Relay application -> Velocity MTA <mark style="color:red;">❌</mark>

SMTP Relay application -> Customer Account -> Postal Route -> Velocity MTA ✅

See instructions on using SMTP Relay with Velocity MTA below:

{% content-ref url="/pages/Zb1Y4kmTg6ZSamRV89En" %}
[Transactional SMTP Relay: steps to start sending](/docs/transactional/transactional-smtp-relay-steps-to-start-sending.md)
{% endcontent-ref %}

{% content-ref url="/pages/9dicqeeYH5F8cv0kteiM" %}
[Transactional SMTP Relay](/docs/transactional/transactional-smtp-relay.md)
{% endcontent-ref %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.emaildelivery.com/docs/what-you-need-to-know-before-you-install-velocity-mta/how-to-use-velocity-mta-as-an-smtp-relay.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.