help needed: dns configuration for dynamic IP & backup smtp

[glenndm]

Hello all,

I'm looking for some guidance for a correct dns setup for a zimbra server together with a hosted domain.

Our domain and homepage are hosted by bluehost.
let's say domain=mycompany.com

At the moment, zimbra downloads mail from bluehost via pop3. Outgoing mail is sent via smart relay host of my local ISP.
mailaddresses are styled: joe@mycompany.com
The server sits behind a dynamic IP and a router with forwarded 25 port.
a Dyndns hostname (mycompany.mine.nu) points to that IP.

First: I'd like zimbra to act as an smtp server for incoming mail to benefit from it's spam/antivirus filters.
Second: I want the bluehost smtp server to be a backup smtp server when mine goes down or it's external ip changes (very rarely)

* Bluehost support stated I should modify the bluehost MX table as follows:
mycompany.com MX 0 mycompany.mine.nu
mycompany.com MX 10 mycompany.com

* on my zimbra server I set dns up as follows:
named.conf.local
zone "mycompany.com" IN {
type master;
file "/etc/bind/db.truckle.mycompany.com";
};

truckle is the zimbra machine's hostname. for those curious, I refer to Terry Pratchett's book 'The Last Hero' for its true meaning.

db.truckle.mycompany.com
$TTL 604800
@ IN SOA truckle. truckle.mycompany.com. (
10118 ; Serial
43200 ; Refresh
3600 ; Retry
3600000 ; Expire
604800 ) ; Minimum
;
@ IN NS truckle.
@ IN NS truckle.mycompany.com.
@ IN MX 10 mycompany.com.
@ IN A 192.168.54.11
truckle IN A 192.168.54.11

------------------------

Could somebody confirm if this setup is correct/workable?

minor problems I see, are:
-from the zimbra server, I will not be able to resolve the bluehost IP relative to the hosted mycompany.com.
-nor can the bluehost smtp server mail.mycompany.com be resolved.

both are (I think) not essential, as the outgoing mail still will go via smart relay host of my local ISP.

best regards
glenn

[phoenix]

If you are behind a NAT router then you'll need a Split DNS set-up. Follow the instructions on that page and see how you get on.

[glenndm]

split-dns procedure has been followed and is working on my server.
dig mx mycompany.com returns the local address as it should.

I just want to make sure the described external setup at bluehost is correct before i switch it over for real.
that the zimbra server will not resolve the external mycompany.com, is not important. I'm more worried about it not resolving the external mail.mycompany.com at bluehost

merci pour votre reponse.
glenn

[phoenix]

I can never remember if 0 (zero) is a valid priority for an MX record so I'd change them to 10 & 20 but otherwise they should be OK. You can always check your DNS via this link: Quick Check - Pingability.com

[glenndm]

ok so nothing jumps out as really wrong.
nothing left than to try it out, i guess
thank you

[glenndm]

I bought the MailHop Relay Zone service from dyndns.org

The hosting (bluehost) mx record points to dyndns mailhop servers, which in turn points to my dynamic dns hostname.
furthermore mailhop delivers mail to my router at port 2525 which internally gets redirected to zimbra port 25. As such I can also circumvent my local ISP block on port 25

When/if I take the server offline, I put my dyndns hostname in offline mode. Further incoming mail get stored at dyndns.org server until my server is back online.

thanks for the help
glenn

[phoenix]

That sounds like a plan. Enjoy and if you have any problems/questions you know where we are.

[Dellster]

Originally Posted by glenndm

I bought the MailHop Relay Zone service from dyndns.org

The hosting (bluehost) mx record points to dyndns mailhop servers, which in turn points to my dynamic dns hostname.
furthermore mailhop delivers mail to my router at port 2525 which internally gets redirected to zimbra port 25. As such I can also circumvent my local ISP block on port 25

When/if I take the server offline, I put my dyndns hostname in offline mode. Further incoming mail get stored at dyndns.org server until my server is back online.

thanks for the help
glenn

Really Nice!