DNS Error for Email Server (errors 11001, 0x800CCC0D, and 0x800409

My Vista Ultimate and Vista Basic machines (desktop and laptop, respectively)
have an intermittent DNS error with a webpage (http://mail.mydomain.com) that
my XP desktop does not experience with the identical internet connection. (If
I run home and use a different internet connection with the Vista laptop, it
works fine during an outage, notwithstanding that the outage continues at my
office.) So the problem seems related to Vista and my ISP (i.e., non-Vista
machine works on my ISP, Vista machine works on another ISP). I also
experience this problem with POP3 to Microsft Outlook, but the issue has
nothing to do with my Outlook account settings: they work intermittently, and
when they fail, my browsers (IE 8, Firefox, and Safari) cannot load the
http://mail.mydomain.com page, even though my browsers work for all other
purposes. Interestingly, even during an outage, I can send hotmail. When in
Outlook, I get the above-captioned errors (Socket error 11001, 0x800CCC0D,
and 0x80040900).

When I click "Diagnose Connection Problem" from IE 8, I get an error that
"Windows cannot find the host name "mail.mydomain.com" using DNS.

On firewalls, all three machines have the same firewall software and
settings, and I am pretty sure it is not the firewall software.

The Microsoft knowledgebase had a seemingly related write-up
(http://support.microsoft.com/default.aspx/kb/939882), but my Vista machines
have Vista Service Pack 1 and Office Service Pack 2, and when I download the
Hotfix from the referenced write-up, it tells me that the Hotfix is not for
my computer, apparently because (per the write-up) I already have the service
pack that incorporated that hotfix.

The newsgroup to which you posted is dedicated to supporting the
Windows Mail program. I don't see where you mentioned Windows Mail
in your problem description.

You might try different DNS servers. I use the ones supplied by
OpenDNS: http://www.opendns.com/

The web host for mail.mydomain.com may have some flaky entries in
the name server settings. I can't check that out because you did not supply the
actual domain name. When I worked tech support for new domain owners
we often had them substitute the IP address for mail.mydomain.com.
That workaround eliminates any DNS lookup issues.

DNS issues are more on topic in the following newsgroup:
microsoft.public.windows.vista.networking_sharing

--
Gary VanderMolen, MS-MVP (Mail)


"Larry Joseph" <Larry Joseph@discussions.microsoft.com> wrote in message news:400C9569-A2C8-4543-9C5A-E73BBB446A4F@microsoft.com...
> My Vista Ultimate and Vista Basic machines (desktop and laptop, respectively)
> have an intermittent DNS error with a webpage (http://mail.mydomain.com) that
> my XP desktop does not experience with the identical internet connection. (If
> I run home and use a different internet connection with the Vista laptop, it
> works fine during an outage, notwithstanding that the outage continues at my
> office.) So the problem seems related to Vista and my ISP (i.e., non-Vista
> machine works on my ISP, Vista machine works on another ISP). I also
> experience this problem with POP3 to Microsft Outlook, but the issue has
> nothing to do with my Outlook account settings: they work intermittently, and
> when they fail, my browsers (IE 8, Firefox, and Safari) cannot load the
> http://mail.mydomain.com page, even though my browsers work for all other
> purposes. Interestingly, even during an outage, I can send hotmail. When in
> Outlook, I get the above-captioned errors (Socket error 11001, 0x800CCC0D,
> and 0x80040900).
>
> When I click "Diagnose Connection Problem" from IE 8, I get an error that
> "Windows cannot find the host name "mail.mydomain.com" using DNS.
>
> On firewalls, all three machines have the same firewall software and
> settings, and I am pretty sure it is not the firewall software.
>
> The Microsoft knowledgebase had a seemingly related write-up
> (http://support.microsoft.com/default.aspx/kb/939882), but my Vista machines
> have Vista Service Pack 1 and Office Service Pack 2, and when I download the
> Hotfix from the referenced write-up, it tells me that the Hotfix is not for
> my computer, apparently because (per the write-up) I already have the service
> pack that incorporated that hotfix.