Ciao,

ho ricontrollato tutto il codice tramite il sito indicato da KillerWorm, ma non riesco ancora a visualizzare le immagine e la firma. Adesso neanche più con Outlook.
Questo , in teoria, è il codice corretto.

codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html charset=UTF-8" />
    <body>
      <table>
        <p style="margin:0;">
          <br/>
          <br/>
        </p>
        <img alt="" hspace="0" src="cid:uniqueId1" /> 
        <br/>
        <br/>
      </table>
      <a href="https://www.MiaDittaspa.it">MiaDitta Spa</a>
      <br/>
      <br/><b>MiaDitta Spa Newsletter.</b>&nbsp;
      <table>
        <img alt="" hspace="0" src="cid:uniqueId" width="500" height="125" align="baseline" border="0" />
      </table>
      <table>
        <hr style="font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; width: 603px; height: 2px;" />
        <p style="margin:0;">
          <span style="font-family: arial, helvetica, sans-serif; font-size: xx-small;">
            <em><b>&ldquo;Tutela dei dati personali "&nbsp; D. Lgs. n. 196/2003 e Regolamento UE n. 2016/679</b><b><br /></b>
              <em> bla bla bla&nbsp;
                <a href="http://www.MiaDittaspa.eu/import/MiaDitta-Privacy.pdf">www.MiaDittaspa.eu/import/MiaDitta-Privacy.pdf</a>. Grazie per la collaborazione. MiaDitta S.p.A.
              </em>
            </em>
          </span>
        </p>
        <center>
          <span style="font-family: arial, helvetica, sans-serif; font-size: xx-small;">* * * *
          </span>
        </center>
        <p style="margin:0;">
          <span style="font-family: arial, helvetica, sans-serif; font-size: xx-small;"><b>&ldquo;Protection of personal data" Legislative Decree no. 196/2003 and EU Regulation no. 2016/679<br /></b>
            <em>Under Article 13 bal bla bla &nbsp;
              <a href="http://www.MiaDittaspa.eu/import/MiaDitta-Privacy.pdf">www.MiaDittaspa.eu/import/MiaDitta-Privacy.pdf"</a>&nbsp;. Many thanks for your kind co-o.
            </em>
          </span>
        </p>
      </table>
    </body>
  </head>
</html>
Altri suggerimenti?

Grazie di nuovo