mj-divider-border.mjml

<mjml>
  <mj-body>
    <mj-section>
      <mj-column>
        <mj-divider border-width="1px" border-style="dashed" border-color="lightgrey" />
      </mj-column>
    </mj-section>
  </mj-body>
</mjml>