Some installations of Outlook under XP appears
to have a bug negotiating the SMTP-Auth protocol. This problem will only
affect customers using our SMTP-Auth server, most users will be
unaffected by this problem. The problem is that Outlook appears to be
using the POP3 mail server name instead of the SMTP server name when
attempting to connect to the the outbound SMTP server. Since our POP3
server does not perform SMTP-Auth services, the connection fails. This
only occurs when using SMTP-Auth. Connections under regular SMTP use the
correct outbound SMTP server setting.
If your system has this problem, you will be able to receive mail, but
you cannot use our SMTP-Auth service. Ensure that both your Windows and
Outlook installations are up-to-date with all the latest upgrades and
patches applied. If the problem persists, doublecheck with Microsoft to
determine why Outlook is not functioning properly on your workstation.
Also, ensure that third party software installed on your workstation is
not interferring with Outlook; see third party software manufacturer's
If all of the above troubleshooting and repair recommendations are
followed and the problem persists, the only remaining choice is to use
your local ISP's outbound SMTP server, and in non-authenticated mode.
Note: In the vast majority of cases, SMTP-Auth has NO problems working with Outlook XP.