These particular authentication settings are located in the Security tab of you SMTP host configuration (Tools > Internet Options > Sending (SMTP) tab.
I would think that you would not be able to send any mail if your authentication was not working so you may need to confirm that it is configured correctly then follow up with your ISP for additional recommendations.
Keep in mind that the POP3 and SMTP hosts used are identity specific so if you have configured multiple hosts and use multiple identities be sure that all identities are using the correctly configured hosts.
<p>These particular authentication settings are located in the Security tab of you SMTP host configuration (Tools &gt; Internet Options &gt; Sending (SMTP) tab.</p><p>I would think that you would not be able to send any mail if your authentication was not working so you may need to confirm that it is configured correctly then follow up with your ISP for additional recommendations.</p><p>Keep in mind that the POP3 and SMTP hosts used are identity specific so if you have configured multiple hosts and use multiple identities be sure that all identities are using the correctly configured hosts.</p><p>&nbsp;</p>