<p>Go to Tools | Internet Options | Sending (SMTP) | Edit | Security</p><p>That's the Security tab.  At the bottom of that box you'll see the  "Do not use CRAM-MD5 authentication even if it is advertised." Check that box.  </p><p> </p><p> </p><p><span style="font-size: 10pt;"> </span></p>

where is the "Security tab of the SMTP host configuration"?????

Tools | Internet options | Sending | Edit | Security.