mx records and where are my emails a-goin'?

[Brazen]

here is the setup:

company.com
A record to x.y.z.12
MX record to mail1.company.com

mail1.company.com
A record to x.y.z.11

lists.company.com
A record to x.y.z.12

If I send an email to lists.company.com where will it go? My hosting provider says I don't need an mx record for lists.company.com (the A record is for a website) because it will default to the mx record for company.com, hence it will already be sent to mail1.company.com which is what I want

I want emails for users@company.com and users@lists.company.com to go to mail1.bucoks.com, but lists.company.com emails do not show up. There is nothing in the mail1.company.com logs or the firewall logs to suggest emails for lists.company.com are trying to reach the server.

Here is the output from the 'host' command run from my home computer:

brazen@PUTER1:~$ host company.com
company.com has address x.y.z.12
company.com mail is handled by 20 mail1.company.com.

brazen@PUTER1:~$ host mail1.company.com
mail1.company.com has address x.y.z.11

brazen@PUTER1:~$ host lists.company.com
lists.company.com has address x.y.z.12

 

[spidey07]

you need an MX record for lists.domain.com

 

[Brazen]

Originally posted by: spidey07
you need an MX record for lists.domain.com

So an smtp server will NOT use the mx record of a parent domain? I'm not surprised if they are wrong, that's par for the course with them.

 

[spidey07]

It's not the SMTP server. It's just basic DNS.

The first thing a mail server does is query DNS for a mail record for the zone (simple terms = domain), it then has a list of server name to which to send mail. You mail server is asking for the MX record of lists.domain.com. Hence why you don't even see attempts to your mail server.

You can check with NSLOOKUP and see the results. Use the option "set type=MX"

You're setting this up a little kludgey but it should work. lists.domain.com should actually be a sub-domain.

 

[nweaver]

Originally posted by: spidey07
It's not the SMTP server. It's just basic DNS.

The first thing a mail server does is query DNS for a mail record for the zone (simple terms = domain), it then has a list of server name to which to send mail. You mail server is asking for the MX record of lists.domain.com. Hence why you don't even see attempts to your mail server.

You can check with NSLOOKUP and see the results. Use the option "set type=MX"

You're setting this up a little kludgey but it should work. lists.domain.com should actually be a sub-domain.

by subdomain, Spidey means a new zone file, SOA, etc.

Also, if you have access to a linux machine, dig >>>nslookup.

dig mx lists.domain.com would show the MX records for that domain (and would not show any currently)

 

[spidey07]

Originally posted by: nweaver
by subdomain, Spidey means a new zone file, SOA, etc.

Also, if you have access to a linux machine, dig >>>nslookup.

dig mx lists.domain.com would show the MX records for that domain (and would not show any currently)

/rant on

DNS runs the whole freaking world of IP communications. Yet is so misunderstood.

It's not freaking magic! Every single person on this board should pick up DNS for dummies.

It's not a slam as I'm no expert on it. It's just SO FREAKING CRUCIAL to communicating.

 

[nweaver]

Originally posted by: spidey07

Originally posted by: nweaver
by subdomain, Spidey means a new zone file, SOA, etc.

Also, if you have access to a linux machine, dig >>>nslookup.

dig mx lists.domain.com would show the MX records for that domain (and would not show any currently)

/rant on

DNS runs the whole freaking world of IP communications. Yet is so misunderstood.

It's not freaking magic! Every single person on this board should pick up DNS for dummies.

It's not a slam as I'm no expert on it. It's just SO FREAKING CRUCIAL to communicating.

most people (from what I have seen) just run dcpromo and let MS handle DNS, and that's about it...maybe add a few records here and there.

I'm firmly in the camp of "Learn the concepts, then applying them will be pretty easy".

if you understand DNS, then bind9, and MS's implementation both make sense, and work. Same goes for all networking imho. Understanding how thing should work > understanding single hot to use single vendor solutions.

OSI model is a perfect example. Nothing really maps to the OSI model in the real world (not entirely anyway), yet any network person worth their salt knows that "All People Seem To Need Data Processing", and how the real world can/should/does map into that.

 

[kevnich2]

DNS really isn't that hard to understand. It's like a phone book for the internet. A mail server is trying to send mail to a given domain, it queries the proper root server which goes to the proper DNS server handling that domain then looks at the MX record to see which server is handling the email, then sends the mail to that server. If it's for a web address, it's the same thing except that if you type in www.domain.com it then queries to see if www. has either a cname or an a record and then proceeds to find the IP adress for that record and then sends the request to that server. DNS is the root of communication for handling internet requests. If it's not setup properly, well then there will be LOTS of issues as things aren't being routed correctly to the proper hosts.