Re: OE's DNS checking doesn't work

From: Joe User (joeu2004_at_hotmail.com)
Date: 07/24/04 

Date: 24 Jul 2004 00:05:29 -0700

"Ted Smith" <who@com.org.net> wrote:
> Like many of the messages here, my mother's Win98 with OE6 was failing to
> send e-mail messages while at the same time being able to receive them ok.

  Are your "Incoming mail" and "Outgoing mail" servers
  different under Tools / Accounts / Mail / <account-name> / Servers?
  If so, that could explain why incoming works, but not outgoing.

> I talked with tech support at her ISP which also provides her e-mail and he
> had me plug in the IP number in the "Outgoing Mail (SMTP)" field where the
> Domain Name usually goes. When I did that OE6 immediately began sending the
> mail again. After a number of other tests to make sure all the settings
> were correct and the connections were working properly (logging onto the
> internet, browsing, etc) he concluded that our OE6 had lost its ability to
> get IP numbers from the Domain Name Servers.

  If an IP address works, but a hostname does, the problem is
  probably with the interaction with the name server, not with OE6.

  To confirm this, try doing the following:

  1. Click on Start / Run, and enter "cmd"
     (or "command" on the MSWin release).

  2. In the cmd window, enter the command `nslookup <IP-address>`,
     using the IP address that your ISP told you use in the
     "Outgoing mail" field.

  nslookup should report one or more hostnames. Does one of the
  hostnames match the hostname that you were previously using and
  that no longer works?

  My first guess is: the answer is "no". In that case, the ISP
  is implicitly telling you to use a different server for your
  "Outgoing mail".

  Enter the new hostname in the "Outgoing mail" field, and test
  to be sure outgoing mail now works. It might be prudent to ask
  your ISP if that was intentional. Your ISP might want to fix
  whatever problem caused the apparent hostname change.

  Otherwise ....

  3. Enter the command `nslookup <SMTP-server-name>`, using the
     hostname that you originally used in the "Outing mail" field.

  If that does not work, the SMTP-server-name cannot be resolved
  (translated to an IP address) by the name server. The fault
  might be the ISP's; or the problem might be in a name server
  database outside the ISP. In either case, the ISP would be the
  best person to determine this.

  If nslookup works, does it return multiple IP addresses?
  If so ....

  4. Enter the command `ping <IP-address>` for each IP address
     returned by nslookup.

  Do some pings work, but not others?

  If some do not work, there is a routing problem on your PC or
  a topology problem within the ISP's network. You ISP might be
  able to help you.

  It would be especially interesting if the IP address that does
  not work is the __first__ IP address returned by nslookup. It
  would also be interesting if that is __not__ the IP address that
  ISP told you to try.

  In any case ....

  5. Enter the command `nslookup <IP-address>`, using the IP
     address that works with OE.

  Does the hostname match the hostname you were using previously?
  If not ....

  6. Enter the command `nslookup <new-hostname>` to verify that
     the (first) IP address matches the working IP address

     If so, enter the new hostname into the "Outgoing mail" field
     in OE, and verify that outgoing mail now works.

  Explanation: Name servers can return multiple IP address
  for the same hostname, but applications might use only the
  first IP address. If the name server database was changed
  to return a different IP address, that could explain why
  outgoing connectivity fails lately.

  Caveat: Name servers can be configured to return multiple
  IP addresses in a different order for each lookup request.
  This can cause intermittent reoccurrence of the problem, if
  some of those IP addresses do not work.

  Hope this helps. I would be interested in knowing the result
  of the experiments described above.