mj-text-font-family.mjml

<mjml>
  <mj-body>
    <mj-section>
      <mj-column>
        <mj-text font-family="Roboto, Helvetica, Arial, sans-serif">
          with font family
        </mj-text>
      </mj-column>
    </mj-section>
  </mj-body>
</mjml>