Concept behind MX records
 

Even though i've done my homework and did quite a lot of googleing, I couldn't find the answer to one question about mx records, though.

I have a domain with godaddy.com (someaddress@mydomain.tdl). I am using their DNS-manager. I set the MX record of my website to: "myaddress.is-a-geek.com.". (is-a-geek.com" part is from my dyndns.com account). "myaddress.is-a-geek.com" itself (A-record) resolves to my real ip, which my smart ;-) router updates every time the ip changes.

I was wondering if in this case, if i send email to someaddress@mydomain.tdl (my godaddy.com domain), the mail would go to my real ip address (myaddress.is-a-geek.com (A) = 123.123.123.123), and get to my mailserver, behind a firewall, where ports 25 and 110 are open.

Question: Does myaddress.is-a-geek.com need an MX record in order for everything to work??

If it should work, i have some other problems ...:(
Is this how it is supposed work??

Thanks

Your question is confusing to follow (for me at least). Basically I understood you have www.example.com and you have a server set up with an A record pointing to it at your home. Your A record is home.dyndns.com. So just add in an MX record to the dns for www.example.com and the data should be the A record of "home.dyndns.com". Thats all you have to do. No mx record for home.dyndns.com is necessary. MX records are actually just pointer records to A records.

mikey

Im confused on you specific setup, I have never dealt with dyndns.org before. But Im almost certain that you have to have an mx record that points to an ipaddress, not an alias.

At least that is the way I have always thought it was...

No, the MX record for mydomain.tdl is all you need.

If your is-a-geek.com hostname is the same as your LQ username and your box is currently up, the problem is your port 25 is not open on the internet side. If you're behind a NAT router, ensure that TCP 25 is port forwarded to your mail server. Another possibility is your ISP may be blocking port 25 inbound.

telnet 71.xxx.xxx.145 25
Trying 71.xxx.xxx.145...
telnet: Unable to connect to remote host: Connection refused

Thanks, snowbat -- i still have one question, though:
What should telnet say if it CAN connect?

I will try telnet tomorrow.

PS: tdl is supposed to be tld, for "top level domain" -- i guess i need more caffein :D

Something like this:

telnet 192.168.1.5 25
Trying 192.168.1.5...
Connected to Cabra (192.168.1.5).
Escape character is '^]'.
220 localhost ESMTP Postfix (2.0.6) (Mandrake Linux)

Let me add a little bit to the confusion.

wwnexc, dit you check this explanation as well?

jlinkels

I'm now seeing a mail server at the is-a-geek.com host so wwnexc is making progress :)

telnet (REDACTED).is-a-geek.com 25
Trying 71.xxx.xxx.103...
Connected to (REDACTED).is-a-geek.com.
Escape character is '^]'.
220 (REDACTED).com ESMTP
quit
221 goodbye
Connection closed by foreign host