mj-accordion-attributes-font.mjml

<mjml>
  <mj-head>
    <mj-attributes>
      <mj-accordion-title font-family="Georgia, serif" />
    </mj-attributes>
  </mj-head>
  <mj-body>
    <mj-section>
      <mj-column>
        <mj-accordion font-family="Roboto, sans-serif">
          <mj-accordion-element>
            <mj-accordion-title>Inherits the accordion font</mj-accordion-title>
            <mj-accordion-text>Text</mj-accordion-text>
          </mj-accordion-element>
          <mj-accordion-element>
            <mj-accordion-title font-family="Lato, sans-serif">Its own font</mj-accordion-title>
            <mj-accordion-text>Text</mj-accordion-text>
          </mj-accordion-element>
        </mj-accordion>
      </mj-column>
    </mj-section>
  </mj-body>
</mjml>