DNS resolving email address?

  • Thread starter Thread starter Jasper Recto
  • Start date Start date
J

Jasper Recto

Is there a way to see if an the an external DNS server is able to resolve
where an email should go? We have a client that can't receive inbound
email. Outbound email works fine. I want to see if there is an issue with
DNS not know where to route the email. How can I check that? Is there a
way to trace an email and find out where it get's stuck?

Thanks,
Jasper
 
what email server? On Exchange, for example, you have the "Message Tracking
Center" tool that will show you the path the email travels until it leaves
your organization.

To see where "other people" are routing emails to when they want to send
emails to your users, you will do something like this from a command prompt:
nslookup
Enter
server ns1.cisco.com
Enter
set q=MX
Enter
youremaildomainname (e.g. myownnicedomain.org)
Enter


You will see some results like:
myownnicedomain.org MX preference = 5, mail exchanger =
mailserver1.myownnicedomain.org
myownnicedomain.org MX preference = 1, mail exchanger =
mailserver2.myownnicedomain.org

mailserver1.myownnicedomain.org internet address = somePublicIP
mailserver2.myownnicedomain.org internet address = somemorePublicIP

This will tell you whom Cisco's servers think is responsible for receiving
mails for your domain. If you are not shy (or afraid) post your real domain
names and we can test for you.

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
www.akomolafe.com
www.iyaburo.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon
 
:
: Is there a way to see if an the an external DNS server is able to resolve
: where an email should go? We have a client that can't receive inbound
: email. Outbound email works fine. I want to see if there is an issue
with
: DNS not know where to route the email. How can I check that? Is there a
: way to trace an email and find out where it get's stuck?

Can you ping the mail server by name? ip?

--
Roland Hall
/* This information is distributed in the hope that it will be useful, but
without any warranty; without even the implied warranty of merchantability
or fitness for a particular purpose. */
Online Support for IT Professionals -
http://support.microsoft.com/servicedesks/technet/default.asp?fr=0&sd=tech
 
The firewall and router will not forward ICMP calls so we can't ping it.

Jasper
 
:
: The firewall and router will not forward ICMP calls so we can't ping it.

nslookup -q=mx domain.tld

This will return mx records for the domain you specify.

Ex: nslookup -q=mx microsoft.com

Is port 25 open on the firewall inbound?
Does the firewall route external mail IP to internal mail IP address?

On the external DNS, the mx record should point to the external address.
The firewall should route incoming traffic on port 25 to the internal mail
address.

--
Roland Hall
/* This information is distributed in the hope that it will be useful, but
without any warranty; without even the implied warranty of merchantability
or fitness for a particular purpose. */
Online Support for IT Professionals -
http://support.microsoft.com/servicedesks/technet/default.asp?fr=0&sd=tech
 
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