DNS lookup for mail is failing 1

[kevin79]

I am getting some errors in with our outgoing email. I constantly get the error message "Domain of sender address me@domain.com does not resolve". How do I fix this? my domain is cascadeng.com.

Please help!

 

[jmiturbe]

Hello,

Is your domain registered? Is your dns server working properly (the authoritative dns server for your domainname)? Do you own your dns server or you use ISP's one?

Many mail servers do a reverse lookup to check the domainname of the sender so if this domain's dns does not work properly the mail can be rejected.

Looking for your domain's info with nslookup, it doesn't work and when looking with verbose mode it gives a timeout error. I can't fix the error, but it seems that there is trouble with your dns records. If you use the DNS of an ISP, you should ask them for the problem.

Bye,

jmiturbe

 

[kevin79]

We run our own DNS. What kind of issue could this be? What should I look for in DNS to fix it?

Sorry, but I'm a newbie at DNS and I don't have the time to learn it. Luckily, DNS will be moving to our ISP in a month or so.

 

[jmiturbe]

Hello,

I'm not sure because I don't know how to debug the error, but when I try to look for the dns records of your domainame it gives a timeout error. It means that I can't get an answer from the dns responsible of your domain. If you say that you run your dns, maybe this service can be down. Can you check if the dns server is working properly?

The check of the dns server depends on the platform it's running and the type of hosts you have. If both are Unix, on the server you can do:

ps -efa|grep named

to see if the dns server daemon in.named is running. And from another Unix host that has your server as it's dns server, just type nslookup and there type any hostname, for example your mail server hostname. If both tests are satisfactory you can say at least that the dns server is working. Do you have Unix?

jmiturbe

 

[kevin79]

Ok, it looks like cascadeng.com is working now. I'm not sure what happened though. I still have problems with two other domains (cktech.biz and noblepolymers.com). It looks like they are responding to reverse lookups. Any idea's on this one?

 

[ChrisAC]

You have a problem with ns1.cascadeng.com. A whois on that domain shows the SOA to be NS1.CASCADENG.COM.

So, I query NS1.CASCADENG.COM for information about your domain ....

Query: cascadeng.com. Query type: Any record
Recursive query: Yes Authoritative answer: No
Query time: 35021 ms. Server name: ns1.cascadeng.com

No records were found.

Oh dear .. the DNS server that is authorative for your domain doesn't actually have a zone file for your domain.

Luckily for you the second SOA does have a record ..


Query: cascadeng.com. Query type: Any record
Recursive query: Yes Authoritative answer: Yes
Query time: 140 ms. Server name: ns.hosting4u.net

Answer:
cascadeng.com. 86400 SOA ns1.cascadeng.com.
webmaster.cascadeng.com.
2003040911 ; serial
10800 ; refresh (3 hours)
3600 ; retry (1 hour)
604800 ; expire (7 days)
86400 ; minimum (1 day)
cascadeng.com. 86400 MX 30 mail.cascadeng.com.
cascadeng.com. 86400 A 69.0.131.100
cascadeng.com. 86400 NS ns.hosting4u.net.
cascadeng.com. 86400 NS ns1.cascadeng.com.

Additional:
mail.cascadeng.com. 86400 A 12.34.33.74
ns.hosting4u.net. 86400 A 209.15.2.3
ns1.cascadeng.com. 86400 A 69.0.131.100

Chris

**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[ChrisAC]

A whois for cktech.biz shows the SOA as NS1.CASCADENG.COM. This doesn't exist.

Same goes for noblepolymers.com.

Query: noblepolymers.com. Query type: SOA record
Recursive query: Yes Authoritative answer: No
Query time: 20339 ms. Server name: n/a

Lame delegation received from "ns.hosting4u.net." for "noblepolymers.com."

You need to make sure that whatever the whois for the domain shows as the SOA's for your domain that:

1. Those servers exist.

2. They have zone files for those domains and that the SOA records on the zone files match the whois SOA.

Chris.
**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[kevin79]

Thanks for the info. ns1.cascadeng.com used to exist. Unfortunately, our old web host sold us off to a different company which moved our server to a new IP address. They either didn't do it completely or didn't do something correctly and ns1.cascadeng.com is still pointing to the IP address of our old webserver.